diff --git a/src/userChrome.scss b/src/userChrome.scss
index d5a8c88..a8d11cb 100644
--- a/src/userChrome.scss
+++ b/src/userChrome.scss
@@ -33,10 +33,14 @@
 }
 
 /* Fully Dark Mode ************************************************************/
-@import "theme/fully_dark";
+@include Option($fullyDark) {
+  @import "theme/fully_dark";
+}
 
 /* Proton Theme Mode **********************************************************/
-@import "theme/proton_chrome";
+@include Option($protonChrome) {
+  @import "theme/proton_chrome";
+}
 
 /** Decoration ****************************************************************/
 @import "theme/decoration";
diff --git a/src/utils/_option.scss b/src/utils/_option.scss
index 71c4303..3fe56d1 100644
--- a/src/utils/_option.scss
+++ b/src/utils/_option.scss
@@ -6,6 +6,8 @@ $compatibilityTheme: "userChrome.theme.compatibility.theme";
 $compatibilityOS: "userChrome.theme.compatibility.os";
 $systemDefault: "userChrome.theme.system_default";
 $fullyColor: "userChrome.theme.fully_color";
+$darkColor: "userChrome.theme.fully_dark";
+$protonChrome: "userChrome.theme.proton_chrome";
 
 @mixin Option($optionName) {
   @supports -moz-bool-pref("#{$optionName}") {
diff --git a/user.js b/user.js
index d15eb42..58ba914 100644
--- a/user.js
+++ b/user.js
@@ -42,6 +42,8 @@ user_pref("userChrome.theme.compatibility.theme", true);
 user_pref("userChrome.theme.compatibility.os", true);
 user_pref("userChrome.theme.system_default", true);
 user_pref("userChrome.theme.fully_color", true);
+user_pref("userChrome.theme.fully_dark", true);
+user_pref("userChrome.theme.proton_chrome", true);
 
 // ** Useful Options ***********************************************************
 // Integrated calculator at urlbar