i actually have seen both in person and thats what you should really go by.
FOR ME, the black multicolor is beautiful with no patina.. in other words, right out of the store type of thing... like tisdale's. her's is rather new. I see tisdale has a thing for multicolor pieces, since she has several.
The white, in contrast, looks amazing with or without patina. and would definitely in my opinion be named the better one out of the two.
i have the white mc alma i haven't used it yet but i take it out of its dust bag once in a while and just smile hahahaha lame i know. anyway, the colours seem to match better with white (it doesn't look as neon-y as it does on the black, IMO). i prefer the white just because summer is coming and the colours are just so darn cheerful!