I never pick warm colors on palominos...It's kind of an "opposites attract" thing.
Warm colors just over do the..warm..ness.. How to I explain it...
Picking red on a non red base horse always looks great. Say, a dapple grey. Looks AMAZING.
Put red on a red base (or redish tone in general like a bay) horse. It all drowns out. Let's say, overheats with too much red.
However, put a cool color on a red base horse, and it pops and compliments all the tones in the horse.
Turquoise and Purple are also the two colors I already have tack and outfits for, so it's less of a hassle and no extra money going out the door.