If I try all available Color Settings (themes) including downloaded hand full.
And even rig and edit my own custom hcs file (or I suppose you could just edit a downloaded one).
None of them ever change the Channel Editors “tools scroller container's” background color (see sample image) from a hue of about 240 seems like a brighter royal blue.
If some one can tell me what the missing color name in the settings file is I can add it manually to my custom color settings file hcs in my user config folder.