diff --git a/src/userChrome.scss b/src/userChrome.scss
index 4f87589..d5a8c88 100644
--- a/src/userChrome.scss
+++ b/src/userChrome.scss
@@ -28,7 +28,9 @@
   */
 
 @import "theme/proton_color";
-@import "theme/fully_color";
+@include Option($fullyColor) {
+  @import "theme/fully_color";
+}
 
 /* Fully Dark Mode ************************************************************/
 @import "theme/fully_dark";
diff --git a/src/utils/_option.scss b/src/utils/_option.scss
index 2544de8..71c4303 100644
--- a/src/utils/_option.scss
+++ b/src/utils/_option.scss
@@ -5,6 +5,7 @@ $compatibility: "userChrome.theme.compatibility";
 $compatibilityTheme: "userChrome.theme.compatibility.theme";
 $compatibilityOS: "userChrome.theme.compatibility.os";
 $systemDefault: "userChrome.theme.system_default";
+$fullyColor: "userChrome.theme.fully_color";
 
 @mixin Option($optionName) {
   @supports -moz-bool-pref("#{$optionName}") {
diff --git a/user.js b/user.js
index bec8442..d15eb42 100644
--- a/user.js
+++ b/user.js
@@ -41,6 +41,7 @@ user_pref("userChrome.theme.compatibility", true);
 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);
 
 // ** Useful Options ***********************************************************
 // Integrated calculator at urlbar