I have a black bike with gold wheels (proper gold too and not that funny greeny bronze that Ducati painted the frame with) and on the rare occasions they aren't covered in chain lube and brake dust they look absolutely magic.
I don't like black wheels at all, or for that matter carbon front mudguards on yellow or red Ducatis. IMHO, they are too much of a contrast and make the bike look clumsy. Funnily though, I don't mind black wheels on Jap bikes.
........I won't wear black trainers either.