Move the "Show Group Colors" toggle from a per-editor option to a single user preference in the Animation preferences. The Grease Pencil animation channel side panel allows picking a channel color; this now shows a message when channel colors are disabled. The old "Show Group Colors" toggle had to be set per editor, and was on by default. This meant that disabling group colors would require an action for every file, for every editor. It is very hard to select a color that works both as bone color in the 3D Viewport (needs to be bright there) as well as the channel list (needs to be dark there), most animators turn channel list colors off. Differential Revision: https://developer.blender.org/D9391