Ona sidenote, colored items should have the color stated in the inventory prior identification. If i see a lone yellow weapon on the floor, i know it's a magical one, but if the same weapon is in a pile of junk and i pick up everything, i can't see it to know that it's magical.
So there is a clear big gap between PC and player parceptions in a place it , imho, shouldn't be.
Blankets should probably be all brown though, but if they aren't, then i agree with the OP, they should be colored in ASCII too, i only play ASCII, for example.