emacs/doc/misc/modus-themes.org

#+title: Modus themes for GNU Emacs
#+author: Protesilaos Stavrou
#+email: info@protesilaos.com
#+language: en
#+options: ':t toc:nil author:t email:t

#+macro: stable-version 1.3.2
#+macro: release-date 2021-04-18
#+macro: development-version 1.4.0-dev
#+macro: export-date (eval (format-time-string "%F %R %z" (current-time)))
#+macro: file @@texinfo:@file{@@$1@@texinfo:}@@
#+macro: space @@texinfo:@: @@
#+macro: kbd @@texinfo:@kbd{@@$1@@texinfo:}@@

#+texinfo_filename: modus-themes.info
#+texinfo_dir_category: Emacs misc features
#+texinfo_dir_title: Modus Themes: (modus-themes)
#+texinfo_dir_desc: Highly accessible themes (WCAG AAA)
#+texinfo_header: @set MAINTAINERSITE @uref{https://protesilaos.com,maintainer webpage}
#+texinfo_header: @set MAINTAINER Protesilaos Stavrou
#+texinfo_header: @set MAINTAINEREMAIL @email{info@protesilaos.com}
#+texinfo_header: @set MAINTAINERCONTACT @uref{mailto:info@protesilaos.com,contact the maintainer}

#+texinfo: @insertcopying

This manual, written by Protesilaos Stavrou, describes the customization
options for the ~modus-operandi~ and ~modus-vivendi~ themes, and provides
every other piece of information pertinent to them.

The documentation furnished herein corresponds to stable version
{{{stable-version}}}, released on {{{release-date}}}.  Any reference to a newer
feature which does not yet form part of the latest tagged commit, is
explicitly marked as such.

Current development target is {{{development-version}}}.  This manual was
built on {{{export-date}}}.

#+toc: headlines 8 insert TOC here, with eight headline levels

* COPYING
:properties:
:copying: t
:custom_id: h:b14c3fcb-13dd-4144-9d92-2c58b3ed16d3
:end:

Copyright (C) 2020-2021  Free Software Foundation, Inc.

#+begin_quote
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with no
Invariant Sections, with the Front-Cover Texts being “A GNU Manual,” and
with the Back-Cover Texts as in (a) below.  A copy of the license is
included in the section entitled “GNU Free Documentation License.”

(a) The FSF’s Back-Cover Text is: “You have the freedom to copy and
modify this GNU manual.”
#+end_quote

* Overview
:properties:
:custom_id: h:f0f3dbcb-602d-40cf-b918-8f929c441baf
:end:

The Modus themes are designed for accessible readability.  They conform
with the highest standard for color contrast between any given
combination of background and foreground values.  This corresponds to
the WCAG AAA standard, which specifies a minimum rate of distance in
relative luminance of 7:1.

Modus Operandi (~modus-operandi~) is a light theme, while Modus Vivendi
(~modus-vivendi~) is dark.  Each theme's color palette is designed to meet
the needs of the numerous interfaces that are possible in the Emacs
computing environment.

The overarching objective of this project is to always offer accessible
color combinations.  There shall never be a compromise on this
principle.  If there arises an inescapable trade-off between readability
and stylistic considerations, we will always opt for the former.

To ensure that users have a consistently accessible experience, the
themes strive to achieve as close to full face coverage as possible
([[#h:a9c8f29d-7f72-4b54-b74b-ddefe15d6a19][Face coverage]]).

Starting with version 0.12.0 and onwards, the themes are built into GNU
Emacs.

** How do the themes look like
:properties:
:custom_id: h:69b92089-069c-4ba1-9d94-cc3415fc4f87
:end:
#+cindex: Screenshots

Check the web page with [[https://protesilaos.com/modus-themes-pictures/][the screen shots]].  There are lots of scenarios
on display that draw attention to details and important aspects in the
design of the themes.  They also showcase the numerous customization
options.

[[#h:bf1c82f2-46c7-4eb2-ad00-dd11fdd8b53f][Customization options]].

** Learn about the latest changes
:properties:
:custom_id: h:2cc37c36-6c1a-48b2-a010-1050b270ee18
:end:
#+cindex: Changelog

Please refer to the [[https://protesilaos.com/modus-themes-changelog][web page with the change log]].  It is comprehensive
and covers everything that goes into every tagged release of the themes.

* Installation
:properties:
:custom_id: h:1af85373-7f81-4c35-af25-afcef490c111
:end:

The Modus themes are distributed with Emacs starting with version 28.1.
On older versions of Emacs, they can be installed using Emacs' package
manager or manually from their code repository.  There also exist
packages for distributions of GNU/Linux.

** Install manually from source
:properties:
:custom_id: h:da3414b7-1426-46b8-8e76-47b845b76fd0
:end:

In the following example, we are assuming that your Emacs files are
stored in =~/.emacs.d= and that you want to place the Modus themes in
=~/.emacs.d/modus-themes=.

1. Get the source and store it in the desired path by running the
   following in the command line shell:

: $ git clone https://gitlab.com/protesilaos/modus-themes.git ~/.emacs.d/modus-themes

2. Add that path to your known Elisp libraries' list, by placing this
   snippet of Emacs Lisp in your init file (e.g. {{{file(init.el)}}}):

#+begin_src emacs-lisp
(add-to-list 'load-path "~/.emacs.d/modus-themes")
#+end_src

The themes are now ready to be used: [[#h:3f3c3728-1b34-437d-9d0c-b110f5b161a9][Enable and load]].

** Install from the archives
:properties:
:custom_id: h:c4b10085-149f-43e2-bd4d-347f33aee054
:end:

The ~modus-themes~ package is available from the GNU ELPA archive, which
is configured by default.

Prior to querying any package archive, make sure to have updated the
index, with {{{kbd(M-x package-refresh-contents)}}}.  Then all you need to do
is type {{{kbd(M-x package-install)}}} and specify the ~modus-themes~.

Note that older versions of the themes used to be distributed as
standalone packages.  This practice has been discontinued starting with
version 1.0.0 of this project.

Once installed, the themes are ready to be used: [[#h:3f3c3728-1b34-437d-9d0c-b110f5b161a9][Enable and load]].

** Install on GNU/Linux
:properties:
:custom_id: h:da640eb1-95dd-4e86-bb4e-1027b27885f0
:end:

The themes are also available from the archives of some distributions of
GNU/Linux.  These should correspond to a tagged release rather than
building directly from the latest Git commit.  It all depends on the
distro's packaging policies.

*** Debian 11 Bullseye
:properties:
:custom_id: h:7e570360-9ee6-4bc5-8c04-9dc11418a3e4
:end:

The themes are part of Debian 11 Bullseye.  Get them with:

#+begin_src sh
sudo apt install elpa-modus-themes
#+end_src

They are now ready to be used: [[#h:3f3c3728-1b34-437d-9d0c-b110f5b161a9][Enable and load]].

*** GNU Guix
:properties:
:custom_id: h:a4ca52cd-869f-46a5-9e16-4d9665f5b88e
:end:

Users of Guix can get the themes with this command:

#+begin_src sh
guix package -i emacs-modus-themes
#+end_src

They are now ready to be used: [[#h:3f3c3728-1b34-437d-9d0c-b110f5b161a9][Enable and load]].

* Enable and load
:properties:
:custom_id: h:3f3c3728-1b34-437d-9d0c-b110f5b161a9
:end:
#+findex: modus-themes-load-themes
#+findex: modus-themes-toggle
#+findex: modus-themes-load-operandi
#+findex: modus-themes-load-vivendi
#+cindex: Essential configuration
#+vindex: modus-themes-after-load-theme-hook

Users of the built-in themes can load and automatically enable the theme
of their preference by adding either form to their init file:

#+begin_src emacs-lisp
(load-theme 'modus-operandi)            ; Light theme
(load-theme 'modus-vivendi)             ; Dark theme
#+end_src

This is all one needs.

Users of packaged variants of the themes must add a few more lines to
ensure that everything works as intended.  First, one has to require the
main library before loading either theme:

#+begin_src emacs-lisp
(require 'modus-themes)
#+end_src

Then it is recommended to load the individual theme files with the
helper function ~modus-themes-load-themes~:

#+begin_src emacs-lisp
;; Load the theme files before enabling a theme (else you get an error).
(modus-themes-load-themes)
#+end_src

Once the libraries that define the themes are enabled, one can activate
a theme with either of the following expressions:

#+begin_src emacs-lisp
(modus-themes-load-operandi)            ; Light theme
;; OR
(modus-themes-load-vivendi)             ; Dark theme
#+end_src

Changes to the available customization options must always be evaluated
before loading a theme ([[#h:bf1c82f2-46c7-4eb2-ad00-dd11fdd8b53f][Customization Options]]).  This is how a basic
setup could look like:

#+begin_src emacs-lisp
(require 'modus-themes)

;; Your customisations here.  For example:
(setq modus-themes-bold-constructs t
      modus-themes-mode-line '3d)

;; Load the theme files before enabling a theme (else you get an error).
(modus-themes-load-themes)

;; Enable the theme of your preference:
(modus-themes-load-operandi)

;; Optionally add a key binding for the toggle between the themes:
(define-key global-map (kbd "<f5>") #'modus-themes-toggle)
#+end_src

[[#h:e979734c-a9e1-4373-9365-0f2cd36107b8][Sample configuration for use-package]].

With those granted, bear in mind a couple of technical points on
~modus-themes-load-operandi~ and ~modus-themes-load-vivendi~, as well as
~modus-themes-toggle~ which relies on them:

1. Those functions call ~load-theme~.  Some users prefer to opt for
   ~enable-theme~ instead ([[#h:e68560b3-7fb0-42bc-a151-e015948f8a35][Differences between loading and enabling]]).

2. The functions will run the ~modus-themes-after-load-theme-hook~ as
   their final step.  This can be employed for bespoke configurations
   ([[#h:f4651d55-8c07-46aa-b52b-bed1e53463bb][Advanced customization (do-it-yourself)]]).  Experienced users may not
   wish to rely on such a hook and the functions that run it: they may
   prefer a custom solution ([[#h:86f6906b-f090-46cc-9816-1fe8aeb38776][A theme-agnostic hook for theme loading]]).

** Sample configuration for use-package
:properties:
:custom_id: h:e979734c-a9e1-4373-9365-0f2cd36107b8
:end:
#+cindex: use-package configuration

It is common for Emacs users to rely on ~use-package~ for declaring
package configurations in their setup.  We use this as an example:

#+begin_src emacs-lisp
(use-package modus-themes
  :ensure                         ; omit this to use the built-in themes
  :init
  ;; Add all your customizations prior to loading the themes
  (setq modus-themes-slanted-constructs t
        modus-themes-bold-constructs nil
        modus-themes-region 'no-extend)

  ;; Load the theme files before enabling a theme (else you get an error).
  (modus-themes-load-themes)
  :config
  ;; Load the theme of your choice:
  (modus-themes-load-operandi) ;; OR (modus-themes-load-vivendi)
  :bind ("<f5>" . modus-themes-toggle))
#+end_src

[[#h:e68560b3-7fb0-42bc-a151-e015948f8a35][Differences between loading and enabling]].

Note: make sure not to customize the variable ~custom-theme-load-path~
or ~custom-theme-directory~ after the themes' package declaration.  That
will lead to failures in loading the files.  If either or both of those
variables need to be changed, their values should be defined before the
package declaration of the themes.

** Differences between loading and enabling
:properties:
:custom_id: h:e68560b3-7fb0-42bc-a151-e015948f8a35
:end:
#+cindex: load-theme VS enable-theme

The reason we recommend ~load-theme~ instead of the other option of
~enable-theme~ is that the former does a kind of "reset" on the face
specs.  It quite literally loads (or re-loads) the theme.  Whereas the
latter simply puts an already loaded theme at the top of the list of
enabled items, re-using whatever state was last loaded.

As such, ~load-theme~ reads all customizations that may happen during
any given Emacs session: even after the initial setup of a theme.
Examples are calls to ~custom-set-faces~, as well as new values assigned
to the options the Modus themes provide ([[#h:bf1c82f2-46c7-4eb2-ad00-dd11fdd8b53f][Customization Options]]).

Our tests show that ~enable-theme~ does not read such variables anew, so
it might appear to the unsuspecting user that the themes are somehow
broken whenever they try to assign a new value to a customization option
or some face.

This "reset" that ~load-theme~ conducts does, however, come at the cost
of being somewhat slower than ~enable-theme~.  Users who have a stable
setup and who seldom update their variables during a given Emacs
session, are better off using something like this:

#+begin_src emacs-lisp
(require 'modus-themes)
(load-theme 'modus-operandi t t)
(load-theme 'modus-vivendi t t)

(enable-theme 'modus-operandi) ;; OR (enable-theme 'modus-vivendi)
#+end_src

[[#h:e979734c-a9e1-4373-9365-0f2cd36107b8][Sample configuration for use-package]].

With the above granted, other sections of the manual discuss how to
configure custom faces, where ~load-theme~ is expected, though
~enable-theme~ could still apply in stable setups:

[[#h:1487c631-f4fe-490d-8d58-d72ffa3bd474][Case-by-case face specs using the themes' palette]].

[[#h:51ba3547-b8c8-40d6-ba5a-4586477fd4ae][Face specs at scale using the themes' palette]].

* Customization Options
:properties:
:custom_id: h:bf1c82f2-46c7-4eb2-ad00-dd11fdd8b53f
:end:

The Modus themes are highly configurable, though they should work well
without any further tweaks.  By default, all customization options are
set to nil.

Remember that all customization options must be evaluated before loading
a theme ([[#h:3f3c3728-1b34-437d-9d0c-b110f5b161a9][Enable and load]]).

** Option for more bold constructs
:properties:
:alt_title: Bold constructs
:description: Toggle bold constructs in code
:custom_id: h:b25714f6-0fbe-41f6-89b5-6912d304091e
:end:
#+vindex: modus-themes-bold-constructs

Symbol: ~modus-themes-bold-constructs~

Possible values:

1. ~nil~ (default)
2. ~t~

The default is to use a bold typographic weight only when it is
required.

With a non-nil value (~t~) display several syntactic constructs in bold
weight.  This concerns keywords and other important aspects of code
syntax.  It also affects certain mode line indicators and command-line
prompts.

** Option for more slanted constructs
:properties:
:alt_title: Slanted constructs
:description: Toggle slanted constructs (italics) in code
:custom_id: h:977c900d-0d6d-4dbb-82d9-c2aae69543d6
:end:
#+vindex: modus-themes-slanted-constructs

Symbol: ~modus-themes-slanted-constructs~

Possible values:

1. ~nil~ (default)
2. ~t~

The default is to not use slanted text (italics) unless it is absolutely
necessary.

With a non-nil value (~t~) choose to render more faces in slanted text.
This typically affects documentation strings and code comments.

** Option for syntax highlighting
:properties:
:alt_title: Syntax styles
:description: Choose the overall aesthetic of code syntax
:custom_id: h:c119d7b2-fcd4-4e44-890e-5e25733d5e52
:end:
#+vindex: modus-themes-syntax

Symbol: ~modus-themes-syntax~

Possible values:

1. ~nil~ (default)
2. ~faint~
3. ~yellow-comments~
4. ~green-strings~
5. ~yellow-comments-green-strings~
6. ~alt-syntax~
7. ~alt-syntax-yellow-comments~
8. ~faint-yellow-comments~

The default style (nil) for code syntax highlighting is a balanced
combination of colors on the cyan-blue-magenta side of the spectrum.
There is little to no use of greens, yellows, or reds, except when it is
necessary.

Option ~faint~ is like the default in terms of the choice of palette but
applies desaturated color values.

Option ~yellow-comments~ adds a yellow tint to comments.  The rest of the
syntax is the same as the default.

Option ~green-strings~ replaces the blue/cyan/cold color variants in
strings with greener alternatives.  The rest of the syntax remains the
same.

Option ~yellow-comments-green-strings~ combines yellow comments with green
strings and the rest of the default syntax highlighting style.

Option ~alt-syntax~ expands the active spectrum by applying color
combinations with more contrasting hues between them.  Expect to find
red and green variants in addition to cyan, blue, magenta.

Option ~alt-syntax-yellow-comments~ combines ~alt-syntax~ with
~yellow-comments~.

Option ~faint-yellow-comments~ combines the ~faint~ style with
~yellow-comments~.

** Option for no font mixing
:properties:
:alt_title: No mixed fonts
:description: Toggle mixing of font families
:custom_id: h:115e6c23-ee35-4a16-8cef-e2fcbb08e28b
:end:
#+vindex: modus-themes-no-mixed-fonts

Symbol: ~modus-themes-no-mixed-fonts~

Possible values:

1. ~nil~ (default)
2. ~t~

By default, the themes configure some spacing-sensitive faces like Org
tables and code blocks to always inherit from the ~fixed-pitch~ face.
This is to ensure that those constructs remain monospaced even when
users opt for a mode that remaps typeface families, such as the built-in
{{{kbd(M-x variable-pitch-mode)}}}.  Otherwise the layout would appear
broken, due to how spacing is done.  To disable this behaviour, set the
option to ~t~.

Users may prefer to use another package for handling mixed typeface
configurations, rather than letting the theme do it, perhaps because a
purpose-specific package has extra functionality.  Two possible options
are ~org-variable-pitch~ and ~mixed-pitch~.

[[#h:defcf4fc-8fa8-4c29-b12e-7119582cc929][Font configurations for Org and others]].

** Option for links
:properties:
:alt_title: Link styles
:description: Choose among several styles, with or without underline
:custom_id: h:c119d7b2-fcd4-4e44-890e-5e25733d5e52
:end:
#+vindex: modus-themes-links

Symbol: ~modus-themes-links~

Possible values:

1. ~nil~ (default)
2. ~faint~
3. ~neutral-underline~
4. ~faint-neutral-underline~
5. ~no-underline~
6. ~underline-only~
7. ~neutral-underline-only~

The default style (nil) for links is to apply an underline and a
saturated color to the affected text.  The color of the two is the same,
which makes the link fairly prominent.

Option ~faint~ follows the same approach as the default, but uses less
intense colors.

Option ~neutral-underline~ changes the underline's color to a subtle gray,
while retaining the default text color.

Option ~faint-neutral-underline~ combines a desaturated text color with a
subtle gray underline.

Option ~no-underline~ removes link underlines altogether, while retaining
their original fairly vivid color.

Option ~underline-only~ applies a prominent underline while making the
affected text colorless (it uses the same foreground as the theme's
default).

Option ~neutral-underline-only~ makes the text colorless while using a
subtle gray underline below it.

NOTE: The placement of the underline, i.e. its proximity to the affected
text, is controlled by the built-in ~x-underline-at-descent-line~,
~x-use-underline-position-properties~, ~underline-minimum-offset~.  Please
refer to their documentation strings.

** Option for command prompt styles
:properties:
:alt_title: Command prompts
:description: Choose among plain, subtle, or intense prompts
:custom_id: h:db5a9a7c-2928-4a28-b0f0-6f2b9bd52ba1
:end:
#+vindex: modus-themes-prompts

Symbol: ~modus-themes-prompts~

Possible values:

1. ~nil~ (default)
2. ~subtle-accented~ (~subtle~ exists for backward compatibility)
3. ~intense-accented~ (~intense~ exists for backward compatibility)
4. ~subtle-gray~
5. ~intense-gray~

The default does not use any background for minibuffer and command line
prompts.  It relies exclusively on an accented foreground color.

Options ~subtle-accented~ and ~intense-accented~ will change both the
background and the foreground values to use accented color combinations
that follow the hue of the default styles' foreground (e.g. the default
minibuffer prompt is cyan text, so these combinations will involved a
cyan background and an appropriate cyan foreground).  The difference
between the two is that the latter has a more pronounced/noticeable
effect than the former.

Options ~subtle-gray~, ~intense-gray~ are like their accented counterparts,
except they use grayscale values.

** Option for mode line presentation
:properties:
:alt_title: Mode line
:description: Choose among several styles, with or without borders
:custom_id: h:27943af6-d950-42d0-bc23-106e43f50a24
:end:
#+vindex: modus-themes-mode-line

Symbol: ~modus-themes-mode-line~

Possible values:

1. ~nil~ (default)
2. ~3d~
3. ~moody~
4. ~borderless~
5. ~borderless-3d~
6. ~borderless-moody~
7. ~accented~
8. ~accented-3d~
9. ~accented-moody~

The default produces a two-dimensional effect both for the active and
inactive modelines.  The differences between the two are limited to
distinct shades of grayscale values, with the active being more intense
than the inactive.

Option ~3d~ will make the active modeline look like a three-dimensional
rectangle.  Inactive modelines remain 2D, though they are slightly toned
down relative to the default.  This aesthetic is virtually the same as
what you get when you run Emacs without any customizations (=emacs -Q= on
the command line).

While ~moody~ removes all box effects from the modelines and applies
underline and overline properties instead.  It also tones down a bit the
inactive modelines.  This is meant to optimize things for use with the
[[https://github.com/tarsius/moody][moody package]] (hereinafter referred to as "Moody"), though it can work
fine even without it.

The ~borderless~ option uses the same colors as the default (nil value),
but removes the border effect.  This is done by making the box property
use the same color as the background, effectively blending the two and
creating some padding.

The ~borderless-3d~ and ~borderless-moody~ approximate the ~3d~ and ~moody~
options respectively, while removing the borders.  However, to ensure
that the inactive modelines remain visible, they apply a slightly more
prominent background to them than what their counterparts do (same
inactive background as with the default).

Similarly, ~accented~, ~accented-3d~, and ~accented-moody~ correspond to the
default (~nil~), ~3d~, and ~moody~ styles respectively, except that the active
mode line uses a colored background instead of the standard shade of
gray.

Note that Moody does not expose any faces that the themes could style
directly.  Instead it re-purposes existing ones to render its tabs and
ribbons.  As such, there may be cases where the contrast ratio falls
below the 7:1 target that the themes conform with (WCAG AAA).  To hedge
against this, we configure a fallback foreground for the ~moody~ option,
which will come into effect when the background of the modeline changes
to something less accessible, such as Moody ribbons (read the doc string
of ~set-face-attribute~, specifically ~:distant-foreground~).  This fallback
is activated when Emacs determines that the background and foreground of
the given construct are too close to each other in terms of color
distance.  In effect, users would need to experiment with the variable
~face-near-same-color-threshold~ to trigger the effect.  We find that a
value of =45000= will suffice, contrary to the default =30000=.  Though for
the ~accented-moody~ value mentioned above, that should be raised up to
=70000=.  Do not set it too high, because it has the adverse effect of
always overriding the default colors (which have been carefully designed
to be highly accessible).

Furthermore, because Moody expects an underline and overline instead of
a box style, it is advised you include this in your setup:

#+begin_src emacs-lisp
(setq x-underline-at-descent-line t)
#+end_src

** Option for completion framework aesthetics
:properties:
:alt_title: Completion UIs
:description: Choose among standard, moderate, or opinionated looks
:custom_id: h:f1c20c02-7b34-4c35-9c65-99170efb2882
:end:
#+vindex: modus-themes-completions

Symbol: ~modus-themes-completions~

Possible values:

1. ~nil~ (default)
2. ~moderate~
3. ~opinionated~

This is a special option that has different effects depending on the
completion UI.  The interfaces can be grouped in two categories, based
on their default aesthetics: (i) those that only or mostly use
foreground colors for their interaction model, and (ii) those that
combine background and foreground values for some of their metaphors.
The former category encompasses Icomplete, Ido, Selectrum as well as
pattern matching styles like Orderless and Flx.  The latter covers Helm,
Ivy, and similar.

A value of ~nil~ will respect the metaphors of each completion framework.

Option ~moderate~ applies a combination of background and foreground that
is fairly subtle.  For Icomplete and friends this constitutes a
departure from their default aesthetics, however the difference is
small.  While Helm, Ivy et al appear slightly different than their
original looks, as they are toned down a bit.

Option ~opinionated~ uses color combinations that refashion the completion
UI.  For the Icomplete camp this means that intense background and
foreground combinations are used: in effect their looks emulate those of
Helm, Ivy and co. in their original style.  Whereas the other group of
packages will revert to an even more nuanced aesthetic with some
additional changes to the choice of hues.

To appreciate the scope of this customization option, you should spend
some time with every one of the ~nil~ (default), ~moderate~, and ~opinionated~
possibilities.

** Option for fringe visibility
:properties:
:alt_title: Fringes
:description: Choose among invisible, subtle, or intense fringe styles
:custom_id: h:1983c3fc-74f6-44f3-b917-967c403bebae
:end:
#+vindex: modus-themes-fringes

Symbol: ~modus-themes-fringes~

Possible values:

1. ~nil~ (default)
2. ~subtle~
3. ~intense~

The default is to use the same color as that of the main background,
meaning that the fringes are not obvious though they still occupy the
space given to them by ~fringe-mode~.

Options ~subtle~ and ~intense~ apply a gray background, making the fringes
visible.  The difference between the two is one of degree, as their
names imply.

** Option for language checkers
:properties:
:alt_title: Language checkers
:description: Control the style of language checkers/linters
:custom_id: h:4b13743a-8ebf-4d2c-a043-cceba10b1eb4
:end:
#+vindex: modus-themes-lang-checkers

Symbol: ~modus-themes-lang-checkers~

Possible values:

1. ~nil~ (default)
2. ~subtle-foreground~
3. ~intense-foreground~
4. ~straight-underline~
5. ~subtle-foreground-straight-underline~
6. ~intense-foreground-straight-underline~
7. ~colored-background~

Nil (the default) applies a color-coded underline to the affected text,
while it leaves the original foreground in tact.  If the display spec
where Emacs runs in has support for it (e.g. Emacs GUI), the underline's
style is that of a wave, otherwise it is a straight line.

Options ~subtle-foreground~ and ~intense-foreground~ follow the same
color-coding pattern and wavy underline of the default, while extending
it with a corresponding foreground value for the affected text.  The
difference between the two options is one of degree, as their names
suggest.

Option ~straight-underline~ is like the default but always applies a
straight line under the affected text.  Same principle for
~subtle-foreground-straight-underline~ and its counterpart
~intense-foreground-straight-underline~.

Option ~colored-background~ uses a straight underline, a tinted
background, and a suitable foreground.  All are color-coded.  This is
the most intense combination of face properties.

The present variable affects packages and/or face groups such as those
of =flyspell=, =flymake=, =flycheck=, ~artbollocks-mode~, and ~writegood-mode~.

NOTE: The placement of the straight underline, though not the wave
style, is controlled by the built-in ~x-underline-at-descent-line~,
~x-use-underline-position-properties~, ~underline-minimum-offset~.  Please
refer to their documentation strings.

** Option for line highlighting (hl-line-mode)
:properties:
:alt_title: Line highlighting
:description: Choose style of current line (hl-line-mode)
:custom_id: h:1dba1cfe-d079-4c13-a810-f768e8789177
:end:
#+vindex: modus-themes-hl-line

Symbol: ~modus-themes-hl-line~

Possible values:

1. ~nil~ (default)
2. ~intense-background~
3. ~accented-background~
4. ~underline-neutral~
5. ~underline-accented~
6. ~underline-only-neutral~
7. ~underline-only-accented~

The default is to use a subtle gray background for the current line when
~hl-line-mode~ is enabled.

The ~intense-background~ applies a more prominent gray to the background
of the current line.

With ~accented-background~ the default's subtle aesthetic is retained, but
the background has a more colored hint.

The ~underline-neutral~ combines the default subtle neutral background
with a gray underline.

Similarly, the ~underline-accented~ renders the background of the current
line in a subtle colored background, while it also draws an accented
underline.

Option ~underline-only-neutral~ produces a neutral underline, but does not
use any background.

While ~underline-only-accented~ also uses just an underline, only this one
is colored.

Consider setting the variable ~x-underline-at-descent-line~ to a non-nil
value for better results with underlines.

This style affects several packages that enable ~hl-line-mode~, such as
=elfeed= and =mu4e=.

** Option for line numbers (display-line-numbers-mode)
:properties:
:alt_title: Line numbers
:description: Toggle subtle style for line numbers
:custom_id: h:8c4a6230-2e43-4aa2-a631-3b7179392e09
:end:
#+vindex: modus-themes-subtle-line-numbers

Symbol: ~modus-themes-subtle-line-numbers~

Possible value:

1. ~nil~ (default)
2. ~t~

The default style for ~display-line-numbers-mode~ and its global variant
is to apply a subtle gray background to the line numbers.  The current
line has a more pronounced background and foreground combination to
bring more attention to itself.

Similarly, the faces for ~display-line-numbers-major-tick~ and its
counterpart ~display-line-numbers-minor-tick~ use appropriate styles that
involve a bespoke background and foreground combination.

With a non-nil value (~t~), line numbers have no background of their own.
Instead they retain the primary background of the theme, blending with
the rest of the buffer.  Foreground values for all relevant faces are
updated to accommodate this aesthetic.

** Option for parenthesis matching (show-paren-mode)
:properties:
:alt_title: Matching parentheses
:description: Choose between various styles for matching delimiters/parentheses
:custom_id: h:e66a7e4d-a512-4bc7-9f86-fbbb5923bf37
:end:
#+vindex: modus-themes-paren-match

Symbol: ~modus-themes-paren-match~

Possible values:

1. ~nil~ (default)
2. ~subtle-bold~
3. ~intense~
4. ~intense-bold~

Nil means to use a subtle tinted background color for the matching
delimiters.

Option ~intense~ applies a saturated background color.

Option ~subtle-bold~ is the same as the default, but also makes use of
bold typographic weight (inherits the ~bold~ face).

Option ~intense-bold~ is the same as ~intense~, while it also uses a bold
weight.

This customization variable affects tools such as the built-in
~show-paren-mode~ and the =smartparens= package.

** Option for active region
:properties:
:alt_title: Active region
:description: Choose between various styles for the active region
:custom_id: h:60798063-b4ad-45ea-b9a7-ff7b5c0ab74c
:end:
#+vindex: modus-themes-region

Symbol: ~modus-themes-region~

Possible values:

1. ~nil~ (default)
2. ~no-extend~
3. ~bg-only~
4. ~bg-only-no-extend~
5. ~accent~
6. ~accent-no-extend~

Nil means to only use a prominent gray background with a neutral
foreground.  The foreground overrides all syntax highlighting.  The
region extends to the edge of the window.

Option ~no-extend~ preserves the default aesthetic but prevents the region
from extending to the edge of the window.

Option ~bg-only~ applies a faint tinted background that is distinct from
all others used in the theme, while it does not override any existing
colors.  It extends to the edge of the window.

Option ~bg-only-no-extend~ is a combination of the ~bg-only~ and ~no-extend~
options.

Option ~accent~ is like the default, though it uses a more colorful
background, while ~accent-no-extend~ is the same except it draws the
region only up to the end of each line instead of extending to the edge
of the window.

** Option for diff buffer looks
:properties:
:alt_title: Diffs
:description: Choose among intense, desaturated, or text-only diffs
:custom_id: h:ea7ac54f-5827-49bd-b09f-62424b3b6427
:end:
#+vindex: modus-themes-diffs

Symbol: ~modus-themes-diffs~

Possible values:

1. ~nil~ (default)
2. ~desaturated~
3. ~fg-only~
4. ~bg-only~
5. ~deuteranopia~

By default the themes apply rich coloration to the output of diffs, such
as those of ~diff-mode~, ~ediff~, ~smerge-mode~, and Magit.  These are
color combinations of an accented background and foreground so that, for
example, added lines have a pronounced green background with an
appropriate shade of green for the affected text.  Word-wise or
"refined" changes follow this pattern but use different shades of those
colors to remain distinct.

Option ~desaturated~ tones down all relevant color values.  It still
combines an accented background with an appropriate foreground, yet its
overall impression is fairly subtle.  Refined changes are a bit more
intense to fulfil their intended function, though still less saturated
than default.

Option ~fg-only~ will remove most accented backgrounds and instead rely
on color-coded text to denote changes.  For instance, added lines use a
green foreground, while their background is the same as the rest of the
buffer.  Word-wise highlights still use a background value which is,
nonetheless, more subtle than its default equivalent.

Option ~bg-only~ applies color-coded backgrounds but does not override
any syntax highlighting that may be present.  This makes it suitable for
use with a non-nil value for ~diff-font-lock-syntax~ (which is the
default for ~diff-mode~ buffers in Emacs 27 or higher).

Option ~deuteranopia~ optimizes for red-green color deficiency.  It
replaces all instances of green with blue variants.  This is to ensure
that indicators for "removed" and "added" states are not mistaken for
each other.

Concerning Magit, an extra set of tweaks are introduced for the effect
of highlighting the current diff hunk, so as to remain aligned with the
overall experience of that mode.  Expect changes that are consistent
with the overall intent of the aforementioned.  Note, however, that the
~bg-only~ option will not deliver the intended results in Magit diffs
because no syntax highlighting is used there (last checked with Magit
version 20201116.1057, though upstream has a plan to eventually support
such a feature---this entry shall be updated accordingly).

** Option for org-mode block styles
:properties:
:alt_title: Org mode blocks
:description: Choose among plain, grayscale, or rainbow styles
:custom_id: h:b7e328c0-3034-4db7-9cdf-d5ba12081ca2
:end:
#+vindex: modus-themes-org-blocks

Symbol: ~modus-themes-org-blocks~

Possible values:

1. ~nil~ (default)
2. ~grayscale~
3. ~rainbow~

The default is to use the same background as the rest of the buffer for
the contents of the block.

Option ~grayscale~ applies a subtle neutral gray background to the block's
contents.  It will also extend to the edge of the window the background
of the "begin" and "end" block delimiter lines (only relevant for Emacs
versions >= 27 where the 'extend' keyword is part of the face
specifications).

Option ~rainbow~ uses an accented background for the contents of the
block.  The exact color will depend on the programming language and is
controlled by the ~org-src-block-faces~ variable.  This is most suitable
for users who work on literate programming documents that mix and match
several languages.

Note that the "rainbow" blocks may require you to also reload the
major-mode so that the colors are applied consistently throughout: use
{{{kbd(M-x org-mode)}}} or {{{kbd(M-x org-mode-restart)}}} to refresh the buffer.
Or start typing in each code block (inefficient at scale, but it still
works).

The extent of Org block delimiter lines is controlled by the variable
~org-fontify-whole-block-delimiter-line~.

** Option for org-habit graph styles
:properties:
:alt_title: Org agenda habits
:description: Choose among standard, simplified, or traffic light styles
:custom_id: h:b7e328c0-3034-4db7-9cdf-d5ba12081ca2
:end:
#+vindex: modus-themes-org-habit

Symbol: ~modus-themes-org-habit~

Possible values:

1. ~nil~ (default)
2. ~simplified~
3. ~traffic-light~

The default is meant to conform with the original aesthetic of
=org-habit=.  It employs all four color codes that correspond to the
org-habit states---clear, ready, alert, and overdue---while
distinguishing between their present and future variants.  This results
in a total of eight colors in use: red, yellow, green, blue, in tinted
and shaded versions.  They cover the full set of information provided by
the =org-habit= consistency graph.

Option ~simplified~ is like the default except that it removes the
dichotomy between current and future variants by applying uniform
color-coded values.  It applies a total of four colors: red, yellow,
green, blue.  They produce a simplified consistency graph that is more
legible (or less "busy") than the default.  The intent is to shift focus
towards the distinction between the four states of a habit task, rather
than each state's present/future outlook.

Option ~traffic-light~ further reduces the available colors to red,
yellow, and green.  As in ~simplified~, present and future variants appear
uniformly, but differently from it, the 'clear' state is rendered in a
green hue, instead of the original blue.  This is meant to capture the
use-case where a habit task being "too early" is less important than it
being "too late".  The difference between ready and clear states is
attenuated by painting both of them using shades of green.  This option
thus highlights the alert and overdue states.

** Option for the headings' overall style
:properties:
:alt_title: Heading styles
:description: Choose among several styles, also per heading level
:custom_id: h:271eff19-97aa-4090-9415-a6463c2f9ae1
:end:
#+vindex: modus-themes-headings

This is defined as an alist and, therefore, uses a different approach
than other customization options documented in this manual.

Symbol: ~modus-themes-headings~

Possible values, which can be specified for each heading level N
(examples further below):

+ ~nil~ (~t~ is also available for backward compatibility)
+ ~no-bold~
+ ~line~
+ ~line-no-bold~
+ ~rainbow~
+ ~rainbow-line~
+ ~rainbow-line-no-bold~
+ ~highlight~
+ ~highlight-no-bold~
+ ~rainbow-highlight~
+ ~rainbow-highlight-no-bold~
+ ~section~
+ ~section-no-bold~
+ ~rainbow-section~
+ ~rainbow-section-no-bold~
+ ~no-color~
+ ~no-color-no-bold~

To control faces per level from 1-8, use something like this:

#+begin_src emacs-lisp
(setq modus-themes-headings
      '((1 . section)
        (2 . section-no-bold)
        (3 . rainbow-line)
        (t . rainbow-line-no-bold)))
#+end_src

The above uses the ~section~ value for heading levels 1, ~section-no-bold~
for headings 2, ~rainbow-line~ for 3.  All other levels fall back to
~rainbow-line-no-bold~.

To set a uniform value for all heading levels, use this pattern:

#+begin_src emacs-lisp
;; A given style for every heading
(setq modus-themes-headings
      '((t . section)))

;; Default aesthetic for every heading
(setq modus-themes-headings nil)
#+end_src

The default style for headings uses a fairly desaturated foreground
color in combination with bold typographic weight.  To specify this
style for a given level N, assuming you wish to have another fallback
option, just assign the value ~nil~ like this:

#+begin_src emacs-lisp
(setq modus-themes-headings
      '((1 . nil)
        (2 . line)
        (3) ; same as nil
        (t . rainbow-line-no-bold)))
#+end_src

A description of all other possible styles beyond the default:

+ ~no-bold~ retains the default text color while removing the bold
  typographic weight.

+ ~line~ is the same as the default plus an overline across the
  heading's length.

+ ~line-no-bold~ is the same as ~line~ without bold weight.

+ ~rainbow~ uses a more colorful foreground in combination with bold
  typographic weight.

+ ~rainbow-line~ is the same as ~rainbow~ plus an overline.

+ ~rainbow-line-no-bold~ is the same as ~rainbow-line~ without the bold
  weight.

+ ~highlight~ retains the default style of a fairly desaturated
  foreground combined with a bold weight and adds to it a subtle
  accented background.

+ ~highlight-no-bold~ is the same as ~highlight~ without a bold weight.

+ ~rainbow-highlight~ is the same as ~highlight~ but with a more
  colorful foreground.

+ ~rainbow-highlight-no-bold~ is the same as ~rainbow-highlight~ without
  a bold weight.

+ ~section~ retains the default looks and adds to them both an overline
  and a slightly accented background.  It is, in effect, a combination
  of the ~line~ and ~highlight~ values.

+ ~section-no-bold~ is the same as ~section~ without a bold weight.

+ ~rainbow-section~ is the same as ~section~ but with a more colorful
  foreground.

+ ~rainbow-section-no-bold~ is the same as ~rainbow-section~ without a
  bold weight.

+ ~no-color~ does not apply any color to the heading, meaning that it
  uses the foreground of the ~default~ face.  It still renders the text
  with a bold typographic weight.

+ ~no-color-no-bold~ is like ~no-color~ but without the bold weight.

Remember to also inspect relevant variables that Org provides, such as:
~org-fontify-whole-heading-line~ and ~org-fontify-done-headline~.

** Option for scaled headings
:properties:
:alt_title: Scaled headings
:description: Toggle scaling of headings
:custom_id: h:075eb022-37a6-41a4-a040-cc189f6bfa1f
:end:
#+vindex: modus-themes-scale-headings

Symbol: ~modus-themes-scale-headings~

Possible values:

1. ~nil~ (default)
2. ~t~

The default is to use the same size for headings and paragraph text.

With a non-nil value (~t~) make headings larger in height relative to the
main text.  This is noticeable in modes like Org, Markdown, and Info.

*** Control the scale of headings
:properties:
:alt_title: Scaled heading sizes
:description: Specify rate of increase for scaled headings
:custom_id: h:6868baa1-beba-45ed-baa5-5fd68322ccb3
:end:

In addition to the toggle for enabling scaled headings, users can also
specify a number of their own.

+ If it is a floating point, say, =1.5=, it is interpreted as a multiple
  of the base font size.  This is the recommended method, because it
  will always adapt to changes in the base font size, such as while
  using the ~text-scale-adjust~ command.

+ If it is an integer, it is read as an absolute font height that is
  1/10 of the typographic point size.  Thus a value of =18pt= must be
  expressed as =180=.  Setting an absolute value is discouraged, as it
  will break the layout in cases where the base font size must change,
  such as with the ~text-scale-adjust~ command ([[#h:defcf4fc-8fa8-4c29-b12e-7119582cc929][Font configurations]]).
  While we discourage using absolute values, we still provide for this
  option for users who do not need to perform text-scaling operations or
  who are content with whatever discrepancies in height.

Below are the variables in their default values, using the floating
point paradigm.  The numbers are very conservative, but one is free to
change them to their liking, such as =1.2=, =1.4=, =1.6=, =1.8=, =2.0=---or use a
resource for finding a consistent scale:

#+begin_src emacs-lisp
(setq modus-themes-scale-1 1.05
      modus-themes-scale-2 1.1
      modus-themes-scale-3 1.15
      modus-themes-scale-4 1.2
      modus-themes-scale-5 1.3)
#+end_src

As for the application of that scale, the variables that range from
~modus-themes-scale-1~ up to ~modus-themes-scale-4~ apply to regular
headings within the context of the given major mode.  The former is the
smallest, while the latter is the largest.  "Regular headings" are those
that have a standard syntax for their scale, such as Org mode's eight
levels of asterisks or Markdown's six columns.

Whereas ~modus-themes-scale-5~ is applied to special headings that do not
conform with the aforementioned syntax, yet which are expected to be
larger than the largest value on that implied scale.  Put concretely,
Org's =#+title= meta datum is not part of the eight levels of headings in
an Org file, yet is supposed to signify the primary header.  Similarly,
the Org Agenda's structure headings are not part of a recognisable scale
and so they also get ~modus-themes-scale-5~.

Users who wish to maintain scaled headings for the normal syntax while
preventing special headings from standing out, can assign a value of =1.0=
to ~modus-themes-scale-5~ to make it the same as body text (or whatever
value would render it indistinguishable from the desired point of
reference).

Note that in earlier versions of Org, scaling would only increase the
size of the heading, but not of keywords that were added to it, like
"TODO".  The issue has been fixed upstream:
<https://protesilaos.com/codelog/2020-09-24-org-headings-adapt/>.

** Option for variable-pitch font in UI elements
:properties:
:alt_title: UI typeface
:description: Toggle the use of variable-pitch across the User Interface
:custom_id: h:16cf666c-5e65-424c-a855-7ea8a4a1fcac
:end:
#+vindex: modus-themes-variable-pitch-ui

Symbol: ~modus-themes-variable-pitch-ui~

Possible values:

1. ~nil~ (default)
2. ~t~

This option concerns User Interface elements that are under the direct
control of Emacs.  In particular: the mode line, header line, tab bar,
and tab line.

The default is to use the same font as the rest of Emacs, which usually
is a monospaced family.

With a non-nil value (~t~) apply a proportionately spaced typeface.  This
is done by assigning the ~variable-pitch~ face to the relevant items.

[[#h:defcf4fc-8fa8-4c29-b12e-7119582cc929][Font configurations for Org and others]].

** Option for variable-pitch font in headings
:properties:
:alt_title: Headings' typeface
:description: Toggle the use of variable-pitch in headings
:custom_id: h:97caca76-fa13-456c-aef1-a2aa165ea274
:end:
#+vindex: modus-themes-variable-pitch-headings

Symbol: ~modus-themes-variable-pitch-headings~

Possible values:

1. ~nil~ (default)
2. ~t~

The default is to use the main font family, which typically is
monospaced.

With a non-nil value (~t~) apply a proportionately spaced typeface, else
"variable-pitch", to headings (such as in Org mode).

[[#h:defcf4fc-8fa8-4c29-b12e-7119582cc929][Font configurations for Org and others]].

* Advanced customization (do-it-yourself)
:properties:
:custom_id: h:f4651d55-8c07-46aa-b52b-bed1e53463bb
:end:

Unlike the predefined customization options which follow a clear pattern
of allowing the user to quickly specify their preference, the themes
also provide a more flexible, albeit difficult, mechanism to control
things with precision ([[#h:bf1c82f2-46c7-4eb2-ad00-dd11fdd8b53f][Customization Options]]).

This section is of interest only to users who are prepared to maintain
their own local tweaks and who are willing to deal with any possible
incompatibilities between versioned releases of the themes.  As such,
they are labelled as "do-it-yourself" or "DIY".

** Per-theme customization settings (DIY)
:properties:
:custom_id: h:a897b302-8e10-4a26-beab-3caaee1e1193
:end:

If you prefer to maintain different customization options between the
two themes, it is best you write your own functions that first set those
options and then load the relevant theme.  The following code does
exactly that by simply differentiating the two themes on the choice of
bold constructs in code syntax (enabled for one, disabled for the
other).

#+begin_src emacs-lisp
(defun my-demo-modus-operandi ()
  (interactive)
  (setq modus-themes-bold-constructs t) ; ENABLE bold
  (modus-themes-load-operandi))

(defun my-demo-modus-vivendi ()
  (interactive)
  (setq modus-themes-bold-constructs nil) ; DISABLE bold
  (modus-themes-load-vivendi))

(defun my-demo-modus-themes-toggle ()
  (if (eq (car custom-enabled-themes) 'modus-operandi)
      (my-demo-modus-vivendi)
    (my-demo-modus-operandi)))
#+end_src

Then assign ~my-demo-modus-themes-toggle~ to a key instead of the
equivalent the themes provide.

For a more elaborate design, it is better to inspect the source code of
~modus-themes-toggle~ and relevant functions.

** Case-by-case face specs using the themes' palette (DIY)
:properties:
:custom_id: h:1487c631-f4fe-490d-8d58-d72ffa3bd474
:end:
#+findex: modus-themes-color
#+findex: modus-themes-color-alts
#+cindex: Extracting individual colors

This section is about tweaking individual faces.  If you plan to do
things at scale, consult the next section: [[#h:51ba3547-b8c8-40d6-ba5a-4586477fd4ae][Set multiple faces]].

We already covered in previous sections how to toggle between the themes
and how to configure options prior to loading.  We also explained that
some of the functions made available to users will fire up a hook that
can be used to pass tweaks in the post-theme-load phase.

Now assume you wish to change a single face, say, the ~cursor~.  And you
would like to get the standard "blue" color value of the active Modus
theme, whether it is Modus Operandi or Modus Vivendi.  To do that, you
can use the ~modus-themes-color~ function.  It accepts a symbol that is
associated with a color in ~modus-themes-operandi-colors~ and
~modus-themes-vivendi-colors~.  Like this:

#+begin_src emacs-lisp
(modus-themes-color 'blue)
#+end_src

The function always extracts the color value of the active Modus theme.

#+begin_src emacs-lisp
(progn
  (load-theme 'modus-operandi t)
  (modus-themes-color 'blue))           ; "#0031a9" for `modus-operandi'

(progn
  (load-theme 'modus-vivendi t)
  (modus-themes-color 'blue))           ; "#2fafff" for `modus-vivendi'
#+end_src

Do {{{kbd(C-h v)}}} on the aforementioned variables to check all the available
symbols that can be passed to this function.

With that granted, let us expand the example to actually change the
~cursor~ face's background property.  We employ the built-in function of
~set-face-attribute~:

#+begin_src emacs-lisp
(set-face-attribute 'cursor nil :background (modus-themes-color 'blue))
#+end_src

If you evaluate this form, your cursor will become blue.  But if you
change themes, such as with ~modus-themes-toggle~, your edits will be
lost, because the newly loaded theme will override the ~:background~
attribute you had assigned to that face.

For such changes to persist, we need to make them after loading the
theme.  So we rely on ~modus-themes-after-load-theme-hook~, which gets
called from ~modus-themes-load-operandi~, ~modus-themes-load-vivendi~, as
well as the command ~modus-themes-toggle~.  Here is a sample function that
tweaks two faces and then gets added to the hook:

#+begin_src emacs-lisp
(defun my-modus-themes-custom-faces ()
  (set-face-attribute 'cursor nil :background (modus-themes-color 'blue))
  (set-face-attribute 'font-lock-type-face nil :foreground (modus-themes-color 'magenta-alt)))

(add-hook 'modus-themes-after-load-theme-hook #'my-modus-themes-custom-faces)
#+end_src

[[#h:86f6906b-f090-46cc-9816-1fe8aeb38776][A theme-agnostic hook for theme loading]].

Using this principle, it is possible to override the styles of faces
without having to find color values for each case.

Another application is to control the precise weight for bold
constructs.  This is particularly useful if your typeface has several
variants such as "heavy", "extrabold", "semibold".  All you have to do
is edit the ~bold~ face.  For example:

#+begin_src emacs-lisp
(set-face-attribute 'bold nil :weight 'semibold)
#+end_src

Remember to use the custom function and hook combo we demonstrated
above.  Because the themes do not hard-wire a specific weight, this
simple form is enough to change the weight of all bold constructs
throughout the interface.

Finally, there are cases where you want to tweak colors though wish to
apply different ones to each theme, say, a blue hue for Modus Operandi
and a shade of red for Modus Vivendi.  To this end, we provide
~modus-themes-color-alts~ as a convenience function to save you from the
trouble of writing separate wrappers for each theme.  It still returns a
single value by querying either of ~modus-themes-operandi-colors~ and
~modus-themes-vivendi-colors~, only here you pass the two keys you want,
first for ~modus-operandi~ then ~modus-vivendi~.

Take the previous example with the ~cursor~ face:

#+begin_src emacs-lisp
;; Blue for `modus-operandi' and red for `modus-vivendi'
(set-face-attribute 'cursor nil :background (modus-themes-color-alts 'blue 'red))
#+end_src

** Face specs at scale using the themes' palette (DIY)
:properties:
:custom_id: h:51ba3547-b8c8-40d6-ba5a-4586477fd4ae
:end:
#+findex: modus-themes-with-colors
#+cindex: Extracting colors en masse

The examples here are for large scale operations.  For simple, one-off
tweaks, you may prefer the approach documented in the previous section
([[#h:1487c631-f4fe-490d-8d58-d72ffa3bd474][Case-by-case face specs using the themes' palette]]).

The ~modus-themes-with-colors~ macro lets you retrieve multiple color
values by employing the backquote/backtick and comma notation.  The
values are stored in the alists ~modus-themes-operandi-colors~ and
~modus-themes-vivendi-colors~, while the macro always queries that of the
active Modus theme.

Here is an abstract example that just returns a list of color values
while ~modus-operandi~ is enabled:

#+begin_src emacs-lisp
(modus-themes-with-colors
  (list fg-main
        blue-faint
        magenta
        magenta-alt-other
        cyan-alt-other
        fg-special-cold
        blue-alt
        magenta-faint
        cyan
        fg-main
        green-faint
        red-alt-faint
        blue-alt-faint
        fg-special-warm
        cyan-alt
        blue))
;; =>
;; ("#000000" "#002f88" "#721045" "#5317ac"
;;  "#005a5f" "#093060" "#2544bb" "#752f50"
;;  "#00538b" "#000000" "#104410" "#702f00"
;;  "#003f78" "#5d3026" "#30517f" "#0031a9")
#+end_src

Getting a list of colors may have its applications, though what you are
most likely interested in is how to use those variables to configure
several faces at once.  To do so we can rely on the built-in
~custom-set-faces~ function, which sets face specifications for the
special ~user~ theme.  That "theme" gets applied on top of regular themes
like ~modus-operandi~ and ~modus-vivendi~.

This is how it works:

#+begin_src emacs-lisp
(modus-themes-with-colors
  (custom-set-faces
   `(cursor ((,class :background ,blue)))
   `(mode-line ((,class :background ,yellow-nuanced-bg
                        :foreground ,yellow-nuanced-fg)))
   `(mode-line-inactive ((,class :background ,blue-nuanced-bg
                                 :foreground ,blue-nuanced-fg)))))
#+end_src

The above snippet will immediately refashion the faces it names once it
is evaluated.  However, if you switch between the Modus themes, say,
from ~modus-operandi~ to ~modus-vivendi~, the colors will not get updated to
match those of the new theme.  To make things work across the themes, we
need to employ the same technique we discussed in the previous section,
namely, to pass our changes at the post-theme-load phase via a hook.

The themes provide the ~modus-themes-after-load-theme-hook~, which gets
called from ~modus-themes-load-operandi~, ~modus-themes-load-vivendi~, as
well as the command ~modus-themes-toggle~.  With this knowledge, you can
wrap the macro in a function and then assign that function to the hook.
Thus:

#+begin_src emacs-lisp
(defun my-modus-themes-custom-faces ()
  (modus-themes-with-colors
    (custom-set-faces
     `(cursor ((,class :background ,blue)))
     `(mode-line ((,class :background ,yellow-nuanced-bg
                          :foreground ,yellow-nuanced-fg)))
     `(mode-line-inactive ((,class :background ,blue-nuanced-bg
                                   :foreground ,blue-nuanced-fg))))))

(add-hook 'modus-themes-after-load-theme-hook #'my-modus-themes-custom-faces)
#+end_src

[[#h:86f6906b-f090-46cc-9816-1fe8aeb38776][A theme-agnostic hook for theme loading]].

To discover the faces defined by all loaded libraries, you may do
{{{kbd(M-x list-faces-display)}}}.  Be warned that when you ~:inherit~ a face
you are introducing an implicit dependency, so try to avoid doing so for
libraries other than the built-in {{{file(faces.el)}}} (or at least understand
that things may break if you inherit from a yet-to-be-loaded face).

Also bear in mind that these examples are meant to work with the Modus
themes.  If you are cycling between multiple themes you may encounter
unforeseen issues, such as the colors of the Modus themes being applied
to a non-Modus item.

Finally, note that you can still use other functions where those make
sense.  For example, the ~modus-themes-color-alts~ that was discussed in
the previous section.  Adapt the above example like this:

#+begin_src emacs-lisp
...
(modus-themes-with-colors
  (custom-set-faces
   `(cursor ((,class :background ,(modus-themes-color-alts 'blue 'green))))
   ...))
#+end_src

** Remap face with local value (DIY)
:properties:
:custom_id: h:7a93cb6f-4eca-4d56-a85c-9dcd813d6b0f
:end:
#+cindex: Remapping faces

There are cases where we need to change the buffer-local attributes of a
face.  This might be because we have our own minor mode that re-uses a
face for a particular purpose, such as a line selection tool that
activates ~hl-line-mode~, but we wish to keep it distinct from other
buffers.  This is where ~face-remap-add-relative~ can be applied and may
be combined with ~modus-themes-with-colors~ to deliver consistent results.

[[#h:51ba3547-b8c8-40d6-ba5a-4586477fd4ae][Face specs at scale using the themes' palette (DIY)]].

In this example we will write a simple interactive function that adjusts
the background color of the ~region~ face.  This is the sample code:

#+begin_src emacs-lisp
(defvar my-rainbow-region-colors
  (modus-themes-with-colors
    `((red . ,red-subtle-bg)
      (green . ,green-subtle-bg)
      (yellow . ,yellow-subtle-bg)
      (blue . ,blue-subtle-bg)
      (magenta . ,magenta-subtle-bg)
      (cyan . ,cyan-subtle-bg)))
  "Sample list of color values for `my-rainbow-region'.")

(defun my-rainbow-region (color)
  "Remap buffer-local attribute of `region' using COLOR."
  (interactive
   (list
    (completing-read "Pick a color: " my-rainbow-region-colors)))
  (face-remap-add-relative
   'region
   `( :background ,(alist-get (intern color) my-rainbow-region-colors)
      :foreground ,(face-attribute 'default :foreground))))
#+end_src

When ~my-rainbow-region~ is called interactively, it prompts for a color
to use.  The list of candidates is drawn from the car of each
association in ~my-rainbow-region-colors~ (so "red", "green", etc.).

To extend this principle, we may write wrapper functions that pass a
color directly.  Those can be useful in tandem with hooks.  Consider
this example:

#+begin_src emacs-lisp
(defun my-rainbow-region-magenta ()
  (my-rainbow-region 'magenta))

(add-hook 'diff-mode-hook #'my-rainbow-region-magenta)
#+end_src

Whenever we enter a ~diff-mode~ buffer, we now get a magenta-colored
region.

Perhaps you may wish to generalise those findings in to a set of
functions that also accept an arbitrary face.  We shall leave the
experimentation up to you.

** Override colors (DIY)
:properties:
:custom_id: h:307d95dd-8dbd-4ece-a543-10ae86f155a6
:end:
#+vindex: modus-themes-operandi-color-overrides
#+vindex: modus-themes-vivendi-color-overrides
#+cindex: Change a theme's colors

The themes provide a mechanism for overriding their color values.  This
is controlled by the variables ~modus-themes-operandi-color-overrides~ and
~modus-themes-vivendi-color-overrides~, which are alists that should
mirror a subset of the associations in ~modus-themes-operandi-colors~ and
~modus-themes-vivendi-colors~ respectively.  As with all customisations,
overriding must be done before loading the affected theme.

Let us approach the present topic one step at a time.  Here is a
simplified excerpt of the default palette for Modus Operandi with some
basic background values that apply to buffers and the mode line
(remember to inspect the actual value to find out all the associations
that can be overridden):

#+begin_src emacs-lisp
(defconst modus-themes-colors-operandi
  '((bg-main . "#ffffff")
    (bg-dim . "#f8f8f8")
    (bg-alt . "#f0f0f0")
    (bg-active . "#d7d7d7")
    (bg-inactive . "#efefef")))
#+end_src

As one can tell, we bind a key to a hexadecimal RGB color value.  Now
say we wish to override those specific values and have our changes
propagate to all faces that use those keys.  We could write something
like this, which adds a subtle ochre tint:

#+begin_src emacs-lisp
(setq modus-themes-operandi-color-overrides
      '((bg-main . "#fefcf4")
        (bg-dim . "#faf6ef")
        (bg-alt . "#f7efe5")
        (bg-active . "#e8dfd1")
        (bg-inactive . "#f6ece5")))
#+end_src

Once this is evaluated, any subsequent loading of ~modus-operandi~ will
use those values instead of the defaults.  No further intervention is
required.

To reset the changes, we apply this and reload the theme:

#+begin_src emacs-lisp
(setq modus-themes-operandi-color-overrides nil)
#+end_src

Users who wish to leverage such a mechanism can opt to implement it
on-demand by means of a global minor mode.  The following snippet covers
both themes and expands to some more assosiations in the palette:

#+begin_src emacs-lisp
(define-minor-mode my-modus-themes-tinted
  "Tweak some Modus themes colors."
  :init-value nil
  :global t
  (if my-modus-themes-tinted
      (setq modus-themes-operandi-color-overrides
            '((bg-main . "#fefcf4")
              (bg-dim . "#faf6ef")
              (bg-alt . "#f7efe5")
              (bg-hl-line . "#f4f0e3")
              (bg-active . "#e8dfd1")
              (bg-inactive . "#f6ece5")
              (bg-region . "#c6bab1")
              (bg-header . "#ede3e0")
              (bg-tab-bar . "#dcd3d3")
              (bg-tab-active . "#fdf6eb")
              (bg-tab-inactive . "#c8bab8")
              (fg-unfocused . "#55556f"))
            modus-themes-vivendi-color-overrides
            '((bg-main . "#100b17")
              (bg-dim . "#161129")
              (bg-alt . "#181732")
              (bg-hl-line . "#191628")
              (bg-active . "#282e46")
              (bg-inactive . "#1a1e39")
              (bg-region . "#393a53")
              (bg-header . "#202037")
              (bg-tab-bar . "#262b41")
              (bg-tab-active . "#120f18")
              (bg-tab-inactive . "#3a3a5a")
              (fg-unfocused . "#9a9aab")))
    (setq modus-themes-operandi-color-overrides nil
          modus-themes-vivendi-color-overrides nil)))
#+end_src

With this in place, one can invoke {{{kbd(M-x my-modus-themes-tinted)}}} and
then load the Modus theme of their choice.  The new palette subset will
come into effect: subtle ochre tints for Modus Operandi and night sky
shades for Modus Vivendi.  Switching between the two themes, such as
with {{{kbd(M-x modus-themes-toggle)}}} will also use the overrides.

Given that this is a user-level customisation, one is free to implement
whatever color values they desire, even if the possible combinations
fall below the minimum 7:1 contrast ratio that governs the design of the
themes (the WCAG AAA legibility standard).  Alternatively, this can also
be done programmatically ([[#h:4589acdc-2505-41fc-9f5e-699cfc45ab00][Override color saturation]]).

For manual interventions it is advised to inspect the source code of
~modus-themes-operandi-colors~ and ~modus-themes-vivendi-colors~ for the
inline commentary: it explains what the intended use of each palette
subset is.

Furthermore, users may benefit from the ~modus-themes-contrast~ function
that we provide: [[#h:02e25930-e71a-493d-828a-8907fc80f874][test color combinations]].  It measures the contrast
ratio between two color values, so it can help in overriding the palette
(or a subset thereof) without making the end result inaccessible.

** Override color saturation (DIY)
:properties:
:custom_id: h:4589acdc-2505-41fc-9f5e-699cfc45ab00
:end:
#+cindex: Change a theme's color saturation

In the previous section we documented how one can override color values
manually ([[#h:307d95dd-8dbd-4ece-a543-10ae86f155a6][Override colors]]).  Here we use a programmatic approach which
leverages the built-in ~color-saturate-name~ function to adjust the
saturation of all color values used by the active Modus theme.  Our goal
is to prepare a counterpart of the active theme's palette that holds
modified color values, adjusted for a percent change in saturation.  A
positive number amplifies the effect, while a negative one will move
towards a grayscale spectrum.

We start with a function that can be either called from Lisp or invoked
interactively.  In the former scenario, we pass to it the rate of change
we want.  While in the latter, a minibuffer prompt asks for a number to
apply the desired effect.  In either case, we intend to assign anew the
value of ~modus-themes-operandi-color-overrides~ (light theme) and the
same for ~modus-themes-vivendi-color-overrides~ (dark theme).

#+begin_src emacs-lisp
(defun my-modus-themes-saturate (percent)
  "Saturate current Modus theme palette overrides by PERCENT."
  (interactive
   (list (read-number "Saturation by percent: ")))
  (let* ((theme (modus-themes--current-theme))
         (palette (pcase theme
                    ('modus-operandi modus-themes-operandi-colors)
                    ('modus-vivendi modus-themes-vivendi-colors)
                    (_ (error "No Modus theme is active"))))
         (overrides (pcase theme
                      ('modus-operandi 'modus-themes-operandi-color-overrides)
                      ('modus-vivendi 'modus-themes-vivendi-color-overrides)
                      (_ (error "No Modus theme is active")))))
    (let (name cons colors)
      (dolist (cons palette)
        (setq name (color-saturate-name (cdr cons) percent))
        (setq name (format "%s" name))
        (setq cons `(,(car cons) . ,name))
        (push cons colors))
      (set overrides colors))
    (pcase theme
      ('modus-operandi (modus-themes-load-operandi))
      ('modus-vivendi (modus-themes-load-vivendi)))))

;; sample Elisp calls (or call `my-modus-themes-saturate' interactively)
(my-modus-themes-saturate 50)
(my-modus-themes-saturate -75)
#+end_src

Using the above has an immediate effect, as it reloads the active Modus
theme.

To disable the effect, one must reset the aforementioned variables to
~nil~.  Or specify a command for it, such as by taking inspiration from
the ~modus-themes-toggle~ we already provide:

#+begin_src emacs-lisp
(defun my-modus-themes-revert-overrides ()
  "Reset palette overrides and reload active Modus theme."
  (interactive)
  (setq modus-themes-operandi-color-overrides nil
        modus-themes-vivendi-color-overrides nil)
  (pcase (modus-themes--current-theme)
    ('modus-operandi (modus-themes-load-operandi))
    ('modus-vivendi (modus-themes-load-vivendi))))
#+end_src

** Font configurations for Org and others (DIY)
:properties:
:custom_id: h:defcf4fc-8fa8-4c29-b12e-7119582cc929
:end:
#+cindex: Font configurations

The themes are designed to cope well with mixed font configurations.

[[#h:115e6c23-ee35-4a16-8cef-e2fcbb08e28b][Option for no font mixing]].

This mostly concerns ~org-mode~ and ~markdown-mode~, though expect to find
it elsewhere like in ~Info-mode~.

In practice it means that the user can safely opt for a more
prose-friendly proportionately spaced typeface as their default, while
letting spacing-sensitive elements like tables and inline code always
use a monospaced font, by inheriting from the ~fixed-pitch~ face.

Users can try the built-in {{{kbd(M-x variable-pitch-mode)}}} to see the
effect in action.

To make everything use your desired font families, you need to configure
the ~variable-pitch~ (proportional spacing) and ~fixed-pitch~ (monospaced)
faces respectively.  It may also be convenient to set your main typeface
by configuring the ~default~ face the same way.

Put something like this in your initialization file (also consider
reading the doc string of ~set-face-attribute~):

#+begin_src emacs-lisp
;; Main typeface
(set-face-attribute 'default nil :family "DejaVu Sans Mono" :height 110)

;; Proportionately spaced typeface
(set-face-attribute 'variable-pitch nil :family "DejaVu Serif" :height 1.0)

;; Monospaced typeface
(set-face-attribute 'fixed-pitch nil :family "DejaVu Sans Mono" :height 1.0)
#+end_src

Note the differences in the ~:height~ property.  The ~default~ face must
specify an absolute value, which is the point size × 10.  So if you want
to use a font at point size =11=, you set the height to =110=.[fn:: ~:height~
values do not need to be rounded to multiples of ten: the likes of =115=
are perfectly valid—some typefaces will change to account for those
finer increments.]  Whereas every other face must have a value that is
relative to the default, represented as a floating point (if you use an
integer, then that means an absolute height).  This is of paramount
importance: it ensures that all fonts can scale gracefully when using
something like the ~text-scale-adjust~ command which only operates on the
base font size (i.e. the ~default~ face's absolute height).

[[#h:e6c5451f-6763-4be7-8fdb-b4706a422a4c][Note for EWW and Elfeed fonts (SHR fonts)]].

** Custom Org user faces (DIY)
:properties:
:custom_id: h:89f0678d-c5c3-4a57-a526-668b2bb2d7ad
:end:
#+cindex: Org extra faces

Users of ~org-mode~ have the option to configure various keywords and
priority cookies to better match their workflow.  User options are
~org-todo-keyword-faces~ and ~org-priority-faces~.

As those are meant to be custom faces, it is futile to have the themes
guess what each user wants to use, which keywords to target, and so on.
Instead, we can provide guidelines on how to customize things to one's
liking with the intent of retaining the overall aesthetic of the themes.

Please bear in mind that the end result of those is not controlled by
the active Modus theme but by how Org maps faces to its constructs.
Editing those while ~org-mode~ is active requires re-initialization of the
mode with {{{kbd(M-x org-mode-restart)}}} for changes to take effect.

Let us assume you wish to visually differentiate your keywords.  You
have something like this:

#+begin_src emacs-lisp
(setq org-todo-keywords
      '((sequence "TODO(t)" "|" "DONE(D)" "CANCEL(C)")
        (sequence "MEET(m)" "|" "MET(M)")
        (sequence "STUDY(s)" "|" "STUDIED(S)")
        (sequence "WRITE(w)" "|" "WROTE(W)")))
#+end_src

You could then use a variant of the following to inherit from a face
that uses the styles you want and also to preserve the properties
applied by the ~org-todo~ face:

#+begin_src emacs-lisp
(setq org-todo-keyword-faces
      '(("MEET" . '(font-lock-preprocessor-face org-todo))
        ("STUDY" . '(font-lock-variable-name-face org-todo))
        ("WRITE" . '(font-lock-type-face org-todo))))
#+end_src

This will refashion the keywords you specify, while letting the other
items in ~org-todo-keywords~ use their original styles (which are defined
in the ~org-todo~ and ~org-done~ faces).

If you want back the defaults, try specifying just the ~org-todo~ face:

#+begin_src emacs-lisp
(setq org-todo-keyword-faces
      '(("MEET" . org-todo)
        ("STUDY" . org-todo)
        ("WRITE" . org-todo)))
#+end_src

When you inherit from multiple faces, you need to quote the list as
shown further above.  The order is important: the last item is applied
over the previous ones.  If you do not want to blend multiple faces, you
do not need a quoted list.  A pattern of =keyword . face= will suffice.

Both approaches can be used simultaneously, as illustrated in this
configuration of the priority cookies:

#+begin_src emacs-lisp
(setq org-priority-faces
      '((?A . '(org-scheduled-today org-priority))
        (?B . org-priority)
        (?C . '(shadow org-priority))))
#+end_src

To find all the faces that are loaded in your current Emacs session, use
{{{kbd(M-x list-faces-display)}}}.  Try {{{kbd(M-x describe-variable)}}} as well and
then specify the name of each of those Org variables demonstrated above.
Their documentation strings will offer you further guidance.

Recall that the themes let you retrieve a color from their palette.  Do
it if you plan to control face attributes.

[[#h:1487c631-f4fe-490d-8d58-d72ffa3bd474][Custom face specs using the themes' palette]].

[[#h:02e25930-e71a-493d-828a-8907fc80f874][Check color combinations]].

** Measure color contrast (DIY)
:properties:
:custom_id: h:02e25930-e71a-493d-828a-8907fc80f874
:end:
#+findex: modus-themes-contrast
#+findex: modus-themes-wcag-formula
#+cindex: Color contrast

The themes provide the functions ~modus-themes-wcag-formula~ and
~modus-themes-contrast~.  The former is a direct implementation of the
WCAG formula: <https://www.w3.org/TR/WCAG20-TECHS/G18.html>.  It
calculates the relative luminance of a color value that is expressed in
hexadecimal RGB notation.  While the latter function is just a
convenient wrapper for comparing the relative luminance between two
colors.

In practice, one needs to work only with ~modus-themes-contrast~.  It
accepts two color values and returns their contrast ratio.  Values range
from 1 to 21 (lowest to highest).  The themes are designed to always be
equal or higher than 7 for each combination of background and foreground
that they use (this is the WCAG AAA standard---the most demanding of its
kind).

A couple of examples (rounded numbers):

#+begin_src emacs-lisp
;; Pure white with pure green
(modus-themes-contrast "#ffffff" "#00ff00")
;; => 1.37
;; That is an outright inaccessible combo

;; Pure black with pure green
(modus-themes-contrast "#000000" "#00ff00")
;; => 15.3
;; That is is a highly accessible combo
#+end_src

It does not matter which color value comes first.  The ratio is always
the same.

If one does not wish to read all the decimal points, it is possible to
try something like this:

#+begin_src emacs-lisp
(format "%0.2f" (modus-themes-contrast "#000000" "#00ff00"))
#+end_src

While it is fine to perform such calculations on a case-by-case basis,
it is preferable to implement formulas and tables for more demanding
tasks.  Such instruments are provided by ~org-mode~ or ~orgtbl-mode~, both
of which are built into Emacs.  Below is such a table that derives the
contrast ratio of all colors in the first column (pure red, green, blue)
relative to the color specified in the first row of the second column
(pure white) and rounds the results:

#+begin_example
|         | #ffffff |
|---------+---------|
| #ff0000 |    4.00 |
| #00ff00 |    1.37 |
| #0000ff |    8.59 |
#+tblfm: $2='(modus-themes-contrast $1 @1$2);%0.2f
#+end_example

To measure color contrast one needs to start from a known value.  This
typically is the background.  The Modus themes define an expanded
palette in large part because certain colors are only meant to be used
in combination with some others.  Consult the source code for the
minutia and relevant commentary.

Such knowledge may prove valuable while attempting to override some of
the themes' colors: [[#h:307d95dd-8dbd-4ece-a543-10ae86f155a6][Override colors]].

** Load theme depending on time of day
:properties:
:custom_id: h:1d1ef4b4-8600-4a09-993c-6de3af0ddd26
:end:

While we do provide ~modus-themes-toggle~ to manually switch between the
themes, users may also set up their system to perform such a task
automatically at sunrise and sunset.

This can be accomplished by specifying the coordinates of one's location
using the built-in {{{file(solar.el)}}} and then configuring the =circadian=
package:

#+begin_src emacs-lisp
(use-package solar                      ; built-in
  :config
  (setq calendar-latitude 35.17
        calendar-longitude 33.36))

(use-package circadian                  ; you need to install this
  :ensure
  :after solar
  (setq circadian-themes '((:sunrise . modus-operandi)
                           (:sunset  . modus-vivendi)))
  (circadian-setup))
#+end_src

** Backdrop for pdf-tools (DIY)
:properties:
:custom_id: h:ff69dfe1-29c0-447a-915c-b5ff7c5509cd
:end:
#+cindex: Remapping pdf-tools backdrop

Most PDF files use a white background for their page, making it
impossible to discern the file's boundaries in the buffer while using
the Modus Operandi theme.  To introduce a distinction between the
buffer's backdrop and the PDF page's background, the former must be
rendered as some shade of gray.  Ideally, ~pdf-tools~ would provide a face
that the themes could support directly, though this does not seem to be
the case for the time being.  We must thus employ the face remapping
technique that is documented elsewhere in this document to change the
buffer-local value of the ~default~ face.

[[#h:7a93cb6f-4eca-4d56-a85c-9dcd813d6b0f][Remap face with local value (DIY)]].

To remap the buffer's backdrop, we start with a function like this one:

#+begin_src emacs-lisp
(defun my-pdf-tools-backdrop ()
  (face-remap-add-relative
   'default
   `(:background ,(modus-themes-color 'bg-alt))))

(add-hook 'pdf-tools-enabled-hook #'my-pdf-tools-backdrop)
#+end_src

The idea is to assign that function to a hook that gets called when
~pdf-tools~ renders the document: ~pdf-tools-enabled-hook~.  This is enough
when you only use one theme.  However it has the downside of setting the
background color value only at render time.  In other words, the face
remapping function does not get evaluated anew whenever the theme
changes, such as upon invoking {{{kbd(M-x modus-themes-toggle)}}}.

To have our face remapping adapt gracefully while switching between the
Modus themes, we need to also account for the current theme and control
the activation of ~pdf-view-midnight-minor-mode~.  To which end we arrive
at something like the following, which builds on the above example:

#+begin_src emacs-lisp
(defun my-pdf-tools-backdrop ()
  (face-remap-add-relative
   'default
   `(:background ,(modus-themes-color 'bg-alt))))

(defun my-pdf-tools-midnight-mode-toggle ()
  (when (derived-mode-p 'pdf-view-mode)
    (if (eq (car custom-enabled-themes) 'modus-vivendi)
        (pdf-view-midnight-minor-mode 1)
      (pdf-view-midnight-minor-mode -1))
    (my-pdf-tools-backdrop)))

(add-hook 'pdf-tools-enabled-hook #'my-pdf-tools-midnight-mode-toggle)
(add-hook 'modus-themes-after-load-theme-hook #'my-pdf-tools-midnight-mode-toggle)
#+end_src

With those in place, PDFs have a distinct backdrop for their page, while
they automatically switch to their dark mode when ~modus-themes-toggle~ is
called from inside a buffer whose major-mode is ~pdf-view-mode~.

** A theme-agnostic hook for theme loading (DIY)
:properties:
:custom_id: h:86f6906b-f090-46cc-9816-1fe8aeb38776
:end:

The themes are designed with the intent to be useful to Emacs users of
varying skill levels, from beginners to experts.  This means that we try
to make things easier by not expecting anyone reading this document to
be proficient in Emacs Lisp or programming in general.

Such a case is with the use of the ~modus-themes-after-load-theme-hook~,
which runs after ~modus-themes-toggle~, ~modus-themes-load-operandi~, or
~modus-themes-load-vivendi~ is evaluated.  We recommend using that hook
for advanced customizations, because (1) we know for sure that it is
available once the themes are loaded, and (2) anyone consulting this
manual, especially the sections on enabling and loading the themes, will
be in a good position to benefit from that hook.

Advanced users who have a need to switch between the Modus themes and
other items will find that such a hook does not meet their requirements:
it only works with the Modus themes and only with the aforementioned
functions.

A theme-agnostic setup can be configured thus:

#+begin_src emacs-lisp
(defvar after-enable-theme-hook nil
   "Normal hook run after enabling a theme.")

(defun run-after-enable-theme-hook (&rest _args)
   "Run `after-enable-theme-hook'."
   (run-hooks 'after-enable-theme-hook))

(advice-add 'enable-theme :after #'run-after-enable-theme-hook)
#+end_src

This creates the ~after-enable-theme-hook~ and makes it run after each
call to ~enable-theme~, which means that it will work for all themes and
also has the benefit that it does not depend on functions such as
~modus-themes-toggle~ and the others mentioned above.  ~enable-theme~ is
called internally by ~load-theme~, so the hook works everywhere.

Now this specific piece of Elisp may be simple for experienced users,
but it is not easy to read for newcomers, including the author of the
Modus themes for the first several months of their time as an Emacs
user.  Hence our hesitation to recommend it as part of the standard
setup of the Modus themes (it is generally a good idea to understand
what the implications are of advising a function).

* Face coverage
:properties:
:custom_id: h:a9c8f29d-7f72-4b54-b74b-ddefe15d6a19
:end:

The Modus themes try to provide as close to full face coverage as
possible.  This is necessary to ensure a consistently accessible reading
experience across all available interfaces.

** Full support for packages or face groups
:properties:
:alt_title: Supported packages
:description: Full list of covered face groups
:custom_id: h:60ed4275-60d6-49f8-9287-9a64e54bea0e
:end:
#+cindex: Explicitly supported packages

This list will always be updated to reflect the current state of the
project.  The idea is to offer an overview of the known status of all
affected face groups.  The items with an appended asterisk =*= tend to
have lots of extensions, so the "full support" may not be 100% true…

+ ace-window
+ ag
+ alert
+ all-the-icons
+ annotate
+ anzu
+ apropos
+ apt-sources-list
+ artbollocks-mode
+ auctex and TeX
+ auto-dim-other-buffers
+ avy
+ awesome-tray
+ bbdb
+ binder
+ bm
+ bongo
+ boon
+ breakpoint (provided by the built-in {{{file(gdb-mi.el)}}} library)
+ buffer-expose
+ calendar and diary
+ calfw
+ centaur-tabs
+ cfrs
+ change-log and log-view (such as ~vc-print-log~, ~vc-print-root-log~)
+ cider
+ circe
+ color-rg
+ column-enforce-mode
+ company-mode*
+ company-posframe
+ compilation-mode
+ completions
+ consult
+ corfu
+ counsel*
+ counsel-css
+ counsel-notmuch
+ counsel-org-capture-string
+ cov
+ cperl-mode
+ csv-mode
+ ctrlf
+ custom (what you get with {{{kbd(M-x customize)}}})
+ dap-mode
+ dashboard (emacs-dashboard)
+ deadgrep
+ debbugs
+ define-word
+ deft
+ dictionary
+ diff-hl
+ diff-mode
+ dim-autoload
+ dir-treeview
+ dired
+ dired-async
+ dired-git
+ dired-git-info
+ dired-narrow
+ dired-subtree
+ diredc
+ diredfl
+ diredp (dired+)
+ disk-usage
+ display-fill-column-indicator-mode
+ doom-modeline
+ dynamic-ruler
+ easy-jekyll
+ easy-kill
+ ebdb
+ ediff
+ eglot
+ el-search
+ eldoc-box
+ elfeed
+ elfeed-score
+ embark
+ emms
+ enh-ruby-mode (enhanced-ruby-mode)
+ epa
+ equake
+ erc
+ eros
+ ert
+ eshell
+ eshell-fringe-status
+ eshell-git-prompt
+ eshell-prompt-extras (epe)
+ eshell-syntax-highlighting
+ evil* (evil-mode)
+ evil-goggles
+ evil-snipe
+ evil-visual-mark-mode
+ eww
+ exwm
+ eyebrowse
+ fancy-dabbrev
+ flycheck
+ flycheck-color-mode-line
+ flycheck-indicator
+ flycheck-posframe
+ flymake
+ flyspell
+ flyspell-correct
+ flx
+ freeze-it
+ frog-menu
+ focus
+ fold-this
+ font-lock (generic syntax highlighting)
+ forge
+ fountain (fountain-mode)
+ geiser
+ git-commit
+ git-gutter (and variants)
+ git-lens
+ git-rebase
+ git-timemachine
+ git-walktree
+ gnus
+ golden-ratio-scroll-screen
+ helm*
+ helm-ls-git
+ helm-switch-shell
+ helm-xref
+ helpful
+ highlight-blocks
+ highlight-defined
+ highlight-escape-sequences (~hes-mode~)
+ highlight-indentation
+ highlight-numbers
+ highlight-symbol
+ highlight-tail
+ highlight-thing
+ hl-defined
+ hl-fill-column
+ hl-line-mode
+ hl-todo
+ hydra
+ hyperlist
+ ibuffer
+ icomplete
+ icomplete-vertical
+ ido-mode
+ iedit
+ iflipb
+ imenu-list
+ indium
+ info
+ info-colors
+ interaction-log
+ ioccur
+ isearch, occur, etc.
+ isl (isearch-light)
+ ivy*
+ ivy-posframe
+ jira (org-jira)
+ journalctl-mode
+ js2-mode
+ julia
+ jupyter
+ kaocha-runner
+ keycast
+ line numbers (~display-line-numbers-mode~ and global variant)
+ lsp-mode
+ lsp-ui
+ macrostep
+ magit
+ magit-imerge
+ make-mode
+ man
+ marginalia
+ markdown-mode
+ markup-faces (~adoc-mode~)
+ mentor
+ messages
+ minibuffer-line
+ minimap
+ mmm-mode
+ modeline
+ mood-line
+ moody
+ mpdel
+ mu4e
+ mu4e-conversation
+ multiple-cursors
+ neotree
+ no-emoji
+ notmuch
+ num3-mode
+ nxml-mode
+ objed
+ orderless
+ org*
+ org-journal
+ org-noter
+ org-pomodoro
+ org-recur
+ org-roam
+ org-superstar
+ org-table-sticky-header
+ org-tree-slide
+ org-treescope
+ origami
+ outline-mode
+ outline-minor-faces
+ package (what you get with {{{kbd(M-x list-packages)}}})
+ page-break-lines
+ pandoc-mode
+ paradox
+ paren-face
+ parrot
+ pass
+ pdf-tools
+ persp-mode
+ perspective
+ phi-grep
+ phi-search
+ pkgbuild-mode
+ pomidor
+ popup
+ powerline
+ powerline-evil
+ prism ([[#h:a94272e0-99da-4149-9e80-11a7e67a2cf2][Note for prism.el]])
+ proced
+ prodigy
+ quick-peek
+ racket-mode
+ rainbow-blocks
+ rainbow-identifiers
+ rainbow-delimiters
+ rcirc
+ recursion-indicator
+ regexp-builder (also known as ~re-builder~)
+ rg (rg.el)
+ ripgrep
+ rmail
+ ruler-mode
+ sallet
+ selectrum
+ selectrum-prescient
+ semantic
+ sesman
+ shell-script-mode
+ shortdoc
+ show-paren-mode
+ shr
+ side-notes
+ sieve-mode
+ skewer-mode
+ smart-mode-line
+ smartparens
+ smerge
+ solaire
+ spaceline
+ speedbar
+ spell-fu
+ spray
+ stripes
+ suggest
+ switch-window
+ swiper
+ swoop
+ sx
+ symbol-overlay
+ syslog-mode
+ tab-bar-groups
+ tab-bar-mode
+ tab-line-mode
+ table (built-in table.el)
+ telega
+ telephone-line
+ terraform-mode
+ term
+ tomatinho
+ transient (pop-up windows such as Magit's)
+ trashed
+ treemacs
+ tty-menu
+ tuareg
+ typescript
+ undo-tree
+ vc (built-in mode line status for version control)
+ vc-annotate (the out put of {{{kbd(C-x v g)}}})
+ vdiff
+ vertico
+ vimish-fold
+ visible-mark
+ visual-regexp
+ volatile-highlights
+ vterm
+ wcheck-mode
+ web-mode
+ wgrep
+ which-function-mode
+ which-key
+ whitespace-mode
+ window-divider-mode
+ winum
+ writegood-mode
+ woman
+ xah-elisp-mode
+ xref
+ xterm-color (and ansi-colors)
+ yaml-mode
+ yasnippet
+ ztree

Plus many other miscellaneous faces that are provided by the upstream
GNU Emacs distribution.

** Indirectly covered packages
:properties:
:custom_id: h:2cb359c7-3a84-4262-bab3-dcdc1d0034d7
:end:
#+cindex: Implicitly supported packages

These do not require any extra styles because they are configured to
inherit from some basic faces.  Please confirm.

+ edit-indirect
+ evil-owl
+ fortran-mode
+ goggles
+ i3wm-config-mode
+ perl-mode
+ php-mode
+ rjsx-mode
+ swift-mode
+ tab-bar-echo-area

* Notes for individual packages
:properties:
:custom_id: h:4c4d901a-84d7-4f20-bd99-0808c2b06eba
:end:

This section covers information that may be of interest to users of
individual packages.

** Note for dimmer.el
:properties:
:custom_id: h:8eb4b758-d318-4480-9ead-357a571beb93
:end:

The {{{file(dimmer.el)}}} library by Neil Okamoto can be configured to
automatically dim the colors of inactive Emacs windows.  To guarantee
consistent results with the Modus themes, we suggest some tweaks to the
default styles, such as in this minimal setup:

#+begin_src emacs-lisp
(use-package dimmer
  :config
  (setq dimmer-fraction 0.3)
  (setq dimmer-adjustment-mode :foreground)
  (setq dimmer-use-colorspace :rgb)

  (dimmer-mode 1))
#+end_src

Of the above, we strongly recommend the RGB color space because it is
the one that remains faithful to the hueness of the colors used by the
themes.  Whereas the default CIELAB space has a tendency to distort
colors in addition to applying the dim effect, which can be somewhat
disorienting.

The value of the ~dimmer-fraction~ has been selected empirically.  Users
might prefer to tweak it further (increasing it makes the dim effect
more pronounced).

Changing the ~dimmer-adjustment-mode~ is a matter of preference.  Though
because the Modus themes use black and white as their base colors, any
other value for that variable will turn the main background gray.  This
inadvertently leads to the opposite of the intended utility of this
package: it draws too much attention to unfocused windows.

** Note for display-fill-column-indicator-mode
:properties:
:custom_id: h:2a602816-bc1b-45bf-9675-4cbbd7bf6cab
:end:

While designing the style for ~display-fill-column-indicator-mode~, we
stayed close to the mode's defaults: to apply a subtle foreground color
to the ~fill-column-indicator~ face, which blends well with the rest of
theme and is consistent with the role of that mode.  This is to not
upset the expectations of users.

Nevertheless, ~display-fill-column-indicator-mode~ has some known
limitations pertaining to its choice of using typographic characters to
draw its indicator.  What should be a continuous vertical line might
appear as a series of dashes in certain contexts or under specific
conditions: a non-default value for ~line-spacing~, scaled and/or
variable-pitch headings have been observed to cause this effect.

Given that we cannot control such factors, it may be better for affected
users to deviate from the default style of the ~fill-column-indicator~
face.  Instead of setting a foreground color, one could use a background
and have the foreground be indistinguishable from it.  For example:

#+begin_src emacs-lisp
(modus-themes-with-colors
  (custom-set-faces
   `(fill-column-indicator ((,class :background ,bg-inactive
                                    :foreground ,bg-inactive)))))
#+end_src

[[#h:51ba3547-b8c8-40d6-ba5a-4586477fd4ae][Face specs at scale using the themes' palette]].

** Note for mmm-mode.el background colors
:properties:
:custom_id: h:99cf0d6c-e478-4e26-9932-3bf3427d13f6
:end:

The faces used by {{{file(mmm-mode.el)}}} are expected to have a colorful
background, while they should not touch any foreground value.  The idea
is that they must not interfere with existing fontification.  Those
background colors need to be distinct from each other, such as an
unambiguous red juxtaposed with a clear blue.

While this design may be internally consistent with the raison d'être of
that library, it inevitably produces inaccessible color combinations.

There are two competing goals at play:

1. Legibility of the text, understood as the contrast ratio between the
   background and the foreground.

2. Semantic precision of each face which entails faithfulness to
   color-coding of the underlying background.

As the Modus themes are designed with the express purpose of conforming
with the first point, we have to forgo the apparent color-coding of the
background elements.  Instead we use subtle colors that do not undermine
the legibility of the affected text while they still offer a sense of
added context.

Users who might prefer to fall below the minimum 7:1 contrast ratio in
relative luminance (the accessibility target we conform with), can opt
to configure the relevant faces on their own.

[[#h:51ba3547-b8c8-40d6-ba5a-4586477fd4ae][Face specs at scale using the themes' palette]].

This example uses more vivid background colors, though it comes at the
very high cost of degraded legibility.

#+begin_src emacs-lisp
(modus-themes-with-colors
  (custom-set-faces
   `(mmm-cleanup-submode-face ((,class :background ,yellow-refine-bg)))
   `(mmm-code-submode-face ((,class :background ,bg-active)))
   `(mmm-comment-submode-face ((,class :background ,blue-refine-bg)))
   `(mmm-declaration-submode-face ((,class :background ,cyan-refine-bg)))
   `(mmm-default-submode-face ((,class :background ,bg-alt)))
   `(mmm-init-submode-face ((,class :background ,magenta-refine-bg)))
   `(mmm-output-submode-face ((,class :background ,red-refine-bg)))
   `(mmm-special-submode-face ((,class :background ,green-refine-bg)))))
#+end_src

** Note for prism.el
:properties:
:alt_title: Note for prism
:custom_id: h:a94272e0-99da-4149-9e80-11a7e67a2cf2
:end:

This package by Adam Porter, aka "alphapapa" or "github-alphapapa",
implements an alternative to the typical coloration of code.  Instead of
highlighting the syntactic constructs, it applies color to different
levels of depth in the code structure.

As {{{file(prism.el)}}} offers a broad range of customisations, we cannot
style it directly at the theme level: that would run contrary to the
spirit of the package.  Instead, we may offer preset color schemes.
Those should offer a starting point for users to adapt to their needs.

In the following code snippets, we employ the ~modus-themes-with-colors~
macro: [[#h:51ba3547-b8c8-40d6-ba5a-4586477fd4ae][Face specs at scale using the themes' palette]].

These are the minimum recommended settings with 16 colors:

#+begin_src emacs-lisp
(setq prism-num-faces 16)

(prism-set-colors
  :desaturations '(0) ; do not change---may lower the contrast ratio
  :lightens '(0)      ; same
  :colors (modus-themes-with-colors
            (list fg-main
                  magenta
                  cyan-alt-other
                  magenta-alt-other
                  blue
                  magenta-alt
                  cyan-alt
                  red-alt-other
                  green
                  fg-main
                  cyan
                  yellow
                  blue-alt
                  red-alt
                  green-alt-other
                  fg-special-warm)))
#+end_src

With 8 colors:

#+begin_src emacs-lisp
(setq prism-num-faces 8)

(prism-set-colors
  :desaturations '(0) ; do not change---may lower the contrast ratio
  :lightens '(0)      ; same
  :colors (modus-themes-with-colors
            (list fg-special-cold
                  magenta
                  magenta-alt-other
                  cyan-alt-other
                  fg-main
                  blue-alt
                  red-alt-other
                  cyan)))
#+end_src

And this is with 4 colors, which produces results that are the closest
to the themes' default aesthetic:

#+begin_src emacs-lisp
(setq prism-num-faces 4)

(prism-set-colors
  :desaturations '(0) ; do not change---may lower the contrast ratio
  :lightens '(0)      ; same
  :colors (modus-themes-with-colors
            (list fg-main
                  cyan-alt-other
                  magenta-alt-other
                  magenta)))
#+end_src

If you need to apply desaturation and lightening, you can use what the
{{{file(prism.el)}}} documentation recommends, like this (adapting to the
examples with the 4, 8, 16 colors):

#+begin_src emacs-lisp
(prism-set-colors
  :desaturations (cl-loop for i from 0 below 16 collect (* i 2.5))
  :lightens (cl-loop for i from 0 below 16 collect (* i 2.5))
  :colors (modus-themes-with-colors
            (list fg-main
                  cyan-alt-other
                  magenta-alt-other
                  magenta)))
#+end_src

** Note on company-mode overlay pop-up
:properties:
:custom_id: h:20cef8c4-d11f-4053-8b2c-2872925780b1
:end:

By default, the ~company-mode~ pop-up that lists completion candidates is
drawn using an overlay.  This creates alignment issues every time it is
placed above a piece of text that has a different height than the
default.

The solution recommended by the project's maintainer is to use an
alternative front-end for drawing the pop-up which draws child frames
instead of overlays.[fn::
https://github.com/company-mode/company-mode/issues/1010][fn::
https://github.com/tumashu/company-posframe/]

** Note for ERC escaped color sequences
:properties:
:custom_id: h:98bdf319-1e32-4469-8a01-771200fba65c
:end:

The built-in IRC client ~erc~ has the ability to colorise any text using
escape sequences that start with =^C= (inserted with {{{kbd(C-q C-c)}}}) and are
followed by a number for the foreground and background.[fn:: This page
explains the basics, though it is not specific to Emacs:
https://www.mirc.com/colors.html] Possible numbers are 0-15, with the
first entry being the foreground and the second the background,
separated by a comma.  Like this =^C1,6=.  The minimum setup is this:

#+begin_src emacs-lisp
(add-to-list 'erc-modules 'irccontrols)
(setq erc-interpret-controls-p t
      erc-interpret-mirc-color t)
#+end_src

As this allows users the chance to make arbitrary combinations, it is
impossible to guarantee a consistently high contrast ratio.  All we can
we do is provide guidance on the combinations that satisfy the
accessibility standard of the themes:

+ Modus Operandi :: Use foreground color 1 for all backgrounds from
  2-15.  Like so: {{{kbd(C-q C-c1,N)}}} where =N= is the background.

+ Modus Vivendi :: Use foreground color 0 for all backgrounds from
  2-13.  Use foreground =1= for backgrounds 14, 15.

Colors 0 and 1 are white and black respectively.  So combine them
together, if you must.

** Note for powerline or spaceline
:properties:
:custom_id: h:9130a8ba-d8e3-41be-a58b-3cb1eb7b6d17
:end:

Both Powerline and Spaceline package users will likely need to use the
command ~powerline-reset~ whenever they make changes to their themes
and/or modeline setup.

** Note on SHR colors
:properties:
:custom_id: h:4cc767dc-ffef-4c5c-9f10-82eb7b8921bf
:end:

Emacs' HTML rendering library ({{{file(shr.el)}}}) may need explicit
configuration to respect the theme's colors instead of whatever
specifications the webpage provides.

Consult {{{kbd(C-h v shr-use-colors)}}}.


** Note for EWW and Elfeed fonts (SHR fonts)
:properties:
:custom_id: h:e6c5451f-6763-4be7-8fdb-b4706a422a4c
:end:

EWW and Elfeed rely on the Simple HTML Renderer to display their
content.  The {{{file(shr.el)}}} library contains the variable ~shr-use-fonts~
that controls whether the text in the buffer is set to a ~variable-pitch~
typeface (proportionately spaced) or if just retains whatever the
default font family is.  Its default value is non-nil, which means that
~variable-pitch~ is applied.

[[#h:defcf4fc-8fa8-4c29-b12e-7119582cc929][Font configurations for Org and others]].

** Note for Helm grep
:properties:
:custom_id: h:d28879a2-8e4b-4525-986e-14c0f873d229
:end:

There is one face from the Helm package that is meant to highlight the
matches of a grep or grep-like command (=ag= or =ripgrep=).  It is
~helm-grep-match~.  However, this face can only apply when the user does
not pass =--color=always= as a command-line option for their command.

Here is the docstring for that face, which is defined in the
{{{file(helm-grep.el)}}} library (you can always visit the source code with
{{{kbd(M-x find-library)}}}).

#+begin_quote
Face used to highlight grep matches.  Have no effect when grep backend
use "--color="
#+end_quote

The user must either remove =--color= from the flags passed to the grep
function, or explicitly use =--color=never= (or equivalent).  Helm
provides user-facing customization options for controlling the grep
function's parameters, such as ~helm-grep-default-command~ and
~helm-grep-git-grep-command~.

When =--color=always= is in effect, the grep output will use red text in
bold letter forms to present the matching part in the list of
candidates.  That style still meets the contrast ratio target of >= 7:1
(accessibility standard WCAG AAA), because it draws the reference to
ANSI color number 1 (red) from the already-supported array of
~ansi-color-names-vector~.

** Note on vc-annotate-background-mode
:properties:
:custom_id: h:5095cbd1-e17a-419c-93e8-951c186362a3
:end:

Due to the unique way ~vc-annotate~ ({{{kbd(C-x v g)}}}) applies colors, support
for its background mode (~vc-annotate-background-mode~) is disabled at the
theme level.

Normally, such a drastic measure should not belong in a theme: assuming
the user's preferences is bad practice.  However, it has been deemed
necessary in the interest of preserving color contrast accessibility
while still supporting a useful built-in tool.

If there actually is a way to avoid such a course of action, without
prejudice to the accessibility standard of this project, then please
report as much or send patches ([[#h:9c3cd842-14b7-44d7-84b2-a5c8bc3fc3b1][Contributing]]).

** Note on pdf-tools link hints
:properties:
:custom_id: h:2659d13e-b1a5-416c-9a89-7c3ce3a76574
:end:

Hints are drawn by [[https://imagemagick.org/][ImageMagick]], not Emacs, i.e., ImageMagick doesn't
know about the hint face unless you tell ImageMagick about it. By
default, only the foreground and background color attributes are
passed. The below snippet adds to those the various font attributes.  As
it queries various faces, specifically ~pdf-links-read-link~ and the faces
it inherits, it needs to be added to your initialization file after
you've customized any faces.

#+begin_src emacs-lisp
(use-package pdf-links
  :config
  (let ((spec
         (apply #'append
                (mapcar
                 (lambda (name)
                   (list name
                         (face-attribute 'pdf-links-read-link
                                         name nil 'default)))
                 '(:family :width :weight :slant)))))
    (setq pdf-links-read-link-convert-commands
          `("-density"    "96"
            "-family"     ,(plist-get spec :family)
            "-stretch"    ,(let* ((width (plist-get spec :width))
                                  (name (symbol-name width)))
                             (replace-regexp-in-string "-" ""
                                                       (capitalize name)))
            "-weight"     ,(pcase (plist-get spec :weight)
                             ('ultra-light "Thin")
                             ('extra-light "ExtraLight")
                             ('light       "Light")
                             ('semi-bold   "SemiBold")
                             ('bold        "Bold")
                             ('extra-bold  "ExtraBold")
                             ('ultra-bold  "Black")
                             (_weight      "Normal"))
            "-style"      ,(pcase (plist-get spec :slant)
                             ('italic  "Italic")
                             ('oblique "Oblique")
                             (_slant   "Normal"))
            "-pointsize"  "%P"
            "-undercolor" "%f"
            "-fill"       "%b"
            "-draw"       "text %X,%Y '%c'"))))
#+end_src

* Contributing
:properties:
:custom_id: h:9c3cd842-14b7-44d7-84b2-a5c8bc3fc3b1
:end:

This section documents the canonical sources of the themes and the ways
in which you can contribute to their ongoing development.

** Sources of the themes
:properties:
:custom_id: h:89504f1c-c9a1-4bd9-ab39-78fd0eddb47c
:end:
#+cindex: Sources of the themes

The ~modus-operandi~ and ~modus-vivendi~ themes are built into Emacs.
Currently they are in Emacs' git main branch (trunk), which is tracking
the next development release target.

The source code of the themes is [[https://gitlab.com/protesilaos/modus-themes/][available on Gitlab]], for the time
being.  A [[https://github.com/protesilaos/modus-themes/][mirror on Github]] is also on offer.

An HTML version of this manual is provided as an extension of the
[[https://protesilaos.com/modus-themes/][author's personal website]] (does not rely on any non-free code).

** Issues you can help with
:properties:
:custom_id: h:6536c8d5-3f98-43ab-a787-b94120e735e8
:end:
#+cindex: Contributing

A few tasks you can help with:

+ Suggest refinements to packages that are covered.
+ Report packages not covered thus far.
+ Report bugs, inconsistencies, shortcomings.
+ Help expand the documentation of covered-but-not-styled packages.
+ Suggest refinements to the color palette.
+ Help expand this document or any other piece of documentation.
+ Merge requests for code refinements.

[[#h:111773e2-f26f-4b68-8c4f-9794ca6b9633][Patches require copyright assignment to the FSF]].

It is preferable that your feedback includes some screenshots, GIFs, or
short videos, as well as further instructions to reproduce a given
setup.  Though this is not a requirement.

Whatever you do, bear in mind the overarching objective of the Modus
themes: to keep a contrast ratio that is greater or equal to 7:1 between
background and foreground colors.  If a compromise is ever necessary
between aesthetics and accessibility, it shall always be made in the
interest of the latter.

** Patches require copyright assignment to the FSF
:properties:
:custom_id: h:111773e2-f26f-4b68-8c4f-9794ca6b9633
:end:

Code contributions are most welcome.  For any major edit (more than 15
lines, or so, in aggregate per person), you need to make a copyright
assignment to the Free Software Foundation.  This is necessary because
the themes are part of the upstream Emacs distribution: the FSF must at
all times be in a position to enforce the GNU General Public License.

Copyright assignment is a simple process.  Check the request form below
(please adapt it accordingly).  You must write an email to the address
mentioned in the form and then wait for the FSF to send you a legal
agreement.  Sign the document and file it back to them.  This could all
happen via email and take about a week.  You are encouraged to go
through this process.  You only need to do it once.  It will allow you
to make contributions to Emacs in general.

#+begin_example text
Please email the following information to assign@gnu.org, and we
will send you the assignment form for your past and future changes.

Please use your full legal name (in ASCII characters) as the subject
line of the message.
----------------------------------------------------------------------
REQUEST: SEND FORM FOR PAST AND FUTURE CHANGES

[What is the name of the program or package you're contributing to?]

GNU Emacs

[Did you copy any files or text written by someone else in these changes?
Even if that material is free software, we need to know about it.]

Copied a few snippets from the same files I edited.  Their author,
Protesilaos Stavrou, has already assigned copyright to the Free Software
Foundation.

[Do you have an employer who might have a basis to claim to own
your changes?  Do you attend a school which might make such a claim?]


[For the copyright registration, what country are you a citizen of?]


[What year were you born?]


[Please write your email address here.]


[Please write your postal address here.]





[Which files have you changed so far, and which new files have you written
so far?]

#+end_example

* Acknowledgements
:properties:
:custom_id: h:95c3da23-217f-404e-b5f3-56c75760ebcf
:end:
#+cindex: Contributors

The Modus themes are a collective effort.  Every bit of work matters.

+ Author/maintainer :: Protesilaos Stavrou.

+ Contributions to code or documentation :: Anders Johansson, Basil
  L.{{{space()}}} Contovounesios, Carlo Zancanaro, Eli Zaretskii, Kostadin
  Ninev, Madhavan Krishnan, Markus Beppler, Matthew Stevenson, Mauro
  Aranda, Nicolas De Jaeghere, Shreyas Ragavan, Stefan Kangas, Vincent
  Murphy, Xinglu Chen.

+ Ideas and user feedback :: Aaron Jensen, Adam Spiers, Adrian Manea,
  Alex Griffin, Alex Peitsinis, Alexey Shmalko, Alok Singh, Anders
  Johansson, André Alexandre Gomes, Arif Rezai, Basil L.{{{space()}}}
  Contovounesios, Burgess Chang, Christian Tietze, Christopher Dimech,
  Damien Cassou, Daniel Mendler, Dario Gjorgjevski, David Edmondson,
  Davor Rotim, Divan Santana, Emanuele Michele Alberto Monterosso,
  Farasha Euker, Gerry Agbobada, Gianluca Recchia, Gustavo Barros,
  Hörmetjan Yiltiz, Ilja Kocken, Iris Garcia, Jeremy Friesen, John
  Haman, Joshua O'Connor, Kevin Fleming, Kévin Le Gouguec, Kostadin
  Ninev, Len Trigg, Manuel Uberti, Mark Burton, Markus Beppler, Mauro
  Aranda, Michael Goldenberg, Morgan Smith, Murilo Pereira, Nicky van
  Foreest, Nicolas De Jaeghere, Paul Poloskov, Pete Kazmier, Peter Wu,
  Philip K., Pierre Téchoueyres, Roman Rudakov, Ryan Phillips, Sam
  Kleinman, Shreyas Ragavan, Simon Pugnet, Tassilo Horn, Thibaut Verron,
  Trey Merkley, Togan Muftuoglu, Toon Claes, Uri Sharf, Utkarsh Singh,
  Vincent Foley.  As well as users: Ben, CsBigDataHub1, Emacs Contrib,
  Eugene, Fourchaux, Fredrik, Moesasji, Nick, TheBlob42, Trey,
  bepolymathe, doolio, fleimgruber, iSeeU, jixiuf, okamsn, pRot0ta1p.

+ Packaging :: Basil L.{{{space()}}} Contovounesios, Eli Zaretskii, Glenn
  Morris, Mauro Aranda, Richard Stallman, Stefan Kangas (core Emacs),
  Stefan Monnier (GNU Elpa), André Alexandre Gomes, Dimakakos Dimos,
  Morgan Smith, Nicolas Goaziou (Guix), Dhavan Vaidya (Debian).

+ Inspiration for certain features :: Bozhidar Batsov (zenburn-theme),
  Fabrice Niessen (leuven-theme).

Special thanks, in no particular order, to Manuel Uberti and Omar
Antolín Camarena for their long time contributions and insightful
commentary.

* Meta
:properties:
:custom_id: h:13752581-4378-478c-af17-165b6e76bc1b
:end:
#+cindex: Development notes

If you are curious about the principles that govern the development of
this project read the essay [[https://protesilaos.com/codelog/2020-03-17-design-modus-themes-emacs/][On the design of the Modus themes]]
(2020-03-17).

Here are some more publications for those interested in the kind of work
that goes into this project (sometimes the commits also include details
of this sort):

+ [[https://protesilaos.com/codelog/2020-05-10-modus-operandi-palette-review/][Modus Operandi theme subtle palette review]] (2020-05-10)
+ [[https://protesilaos.com/codelog/2020-06-13-modus-vivendi-palette-review/][Modus Vivendi theme subtle palette review]] (2020-06-13)
+ [[https://protesilaos.com/codelog/2020-07-04-modus-themes-faint-colours/][Modus themes: new "faint syntax" option]] (2020-07-04)
+ [[https://protesilaos.com/codelog/2020-07-08-modus-themes-nuanced-colours/][Modus themes: major review of "nuanced" colours]] (2020-07-08)
+ [[https://protesilaos.com/codelog/2020-09-14-modus-themes-review-blues/][Modus themes: review of blue colours]] (2020-09-14)
+ [[https://protesilaos.com/codelog/2020-12-27-modus-themes-review-rainbow-delimiters/][Modus themes: review rainbow-delimiters faces]] (2020-12-27)
+ [[https://protesilaos.com/codelog/2021-01-11-modus-themes-review-select-faint-colours/][Modus themes: review of select "faint" colours]] (2021-01-11)
+ [[https://protesilaos.com/codelog/2021-02-25-modus-themes-diffs-deuteranopia/][The Modus themes now cover deuteranopia in diffs]] (2021-02-25)

And here are the canonical sources of this project's documentation:

+ Manual :: <https://protesilaos.com/modus-themes>
+ Change Log :: <https://protesilaos.com/modus-themes-changelog>
+ Screenshots :: <https://protesilaos.com/modus-themes-pictures>

* GNU Free Documentation License
:properties:
:appendix: t
:custom_id: h:3077c3d2-7f90-4228-8f0a-73124f4026f6
:end:

#+texinfo: @include doclicense.texi

#+begin_export html
<pre>

                GNU Free Documentation License
                 Version 1.3, 3 November 2008


 Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
     <https://fsf.org/>
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.

0. PREAMBLE

The purpose of this License is to make a manual, textbook, or other
functional and useful document "free" in the sense of freedom: to
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Secondarily, this License preserves for the author and publisher a way
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for modifications made by others.

This License is a kind of "copyleft", which means that derivative
works of the document must themselves be free in the same sense.  It
complements the GNU General Public License, which is a copyleft
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We have designed this License in order to use it for manuals for free
software, because free software needs free documentation: a free
program should come with manuals providing the same freedoms that the
software does.  But this License is not limited to software manuals;
it can be used for any textual work, regardless of subject matter or
whether it is published as a printed book.  We recommend this License
principally for works whose purpose is instruction or reference.


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contains a notice placed by the copyright holder saying it can be
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A "Modified Version" of the Document means any work containing the
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or disclaimer, the original version will prevail.

If a section in the Document is Entitled "Acknowledgements",
"Dedications", or "History", the requirement (section 4) to Preserve
its Title (section 1) will typically require changing the actual
title.


9. TERMINATION

You may not copy, modify, sublicense, or distribute the Document
except as expressly provided under this License.  Any attempt
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will automatically terminate your rights under this License.

However, if you cease all violation of this License, then your license
from a particular copyright holder is reinstated (a) provisionally,
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Moreover, your license from a particular copyright holder is
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10. FUTURE REVISIONS OF THIS LICENSE

The Free Software Foundation may publish new, revised versions of the
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"CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0
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The operator of an MMC Site may republish an MMC contained in the site
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ADDENDUM: How to use this License for your documents

To use this License in a document you have written, include a copy of
the License in the document and put the following copyright and
license notices just after the title page:

    Copyright (c)  YEAR  YOUR NAME.
    Permission is granted to copy, distribute and/or modify this document
    under the terms of the GNU Free Documentation License, Version 1.3
    or any later version published by the Free Software Foundation;
    with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
    A copy of the license is included in the section entitled "GNU
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If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts,
replace the "with...Texts." line with this:

    with the Invariant Sections being LIST THEIR TITLES, with the
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If you have Invariant Sections without Cover Texts, or some other
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If your document contains nontrivial examples of program code, we
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</pre>
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