Thomas Baker wrote: [..]
I'll try to find the where the mappings of X colors to features of mutt are defined...
That would be in your ~/.muttrc.There used to be a slew of such mappings at wiki.mutt.org but right now practically all the links appear to be broken.
Useful samples and screenshots: http://www.xs4all.nl/~matto/mutt-themes.html HTH Gen-Paul.