I see that Help:Extension:FlaggedRevs#Current colors has a helpful guide to what FlaggedRevs colors mean on edit lists, but an inline comment says "Found these colors on www.mediawiki.org, and guessed the respective meanings based on a user's contribution list. Don't know if they are the extension's default or a custom version of them specific of that site." - so it sounds like they should be verified. :) I noticed those colors while looking at Wikibooks, and I wrote a comment suggesting improved documentation there as well. Thanks!
Topic on Extension talk:FlaggedRevs
I did what I could - see the diff - let me know if you see any colours that aren't listed there, but I think I got all of 'em.