General: revert [55045].

This changeset reverts [55045] to maintain backward compatibility for developers using the function in their SCSS.

Follow-up to [55045].

Unprops audrasjb.
Props peterwilsoncc, kebbet.
See #56811.


git-svn-id: https://develop.svn.wordpress.org/trunk@55048 602fd350-edb4-49c9-b593-d223f7449a82

Author: audrasjb

src/wp-admin/css/colors/_admin.scss

@@ -2,7 +2,11 @@
 @import 'variables';
 @import 'mixins';
 
-@function url-friendly-color( $color ) {
+/**
+ * This function name uses British English to maintain backward compatibility, as developers
+ * may use the function in their own admin CSS files. See #56811.
+ */
+@function url-friendly-colour( $color ) {
 	@return '%23' + str-slice( '#{ $color }', 2, -1 );
 }
 
@@ -62,7 +66,7 @@ span.wp-media-buttons-icon:before {
 /* Forms */
 
 input[type=checkbox]:checked::before {
-	content: url("data:image/svg+xml;utf8,%3Csvg%20xmlns%3D%27http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%27%20viewBox%3D%270%200%2020%2020%27%3E%3Cpath%20d%3D%27M14.83%204.89l1.34.94-5.81%208.38H9.02L5.78%209.67l1.34-1.25%202.57%202.4z%27%20fill%3D%27#{url-friendly-color($form-checked)}%27%2F%3E%3C%2Fsvg%3E");
+	content: url("data:image/svg+xml;utf8,%3Csvg%20xmlns%3D%27http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%27%20viewBox%3D%270%200%2020%2020%27%3E%3Cpath%20d%3D%27M14.83%204.89l1.34.94-5.81%208.38H9.02L5.78%209.67l1.34-1.25%202.57%202.4z%27%20fill%3D%27#{url-friendly-colour($form-checked)}%27%2F%3E%3C%2Fsvg%3E");
 }
 
 input[type=radio]:checked::before {