@TheBlastmaster: I do sometimes, personally, because I always confuse it with Nintendo's button layout, but I know you're not supposed to. If anything, I prefer the colored look way more.
@roxor3: You may be onto something, however - maybe not, because they did the same thing with the "elite" 360 controller (with a better DPad) and there you couldn't remap anything.
I think they're doing it for the more strict, "professional" and expensive look of the whole thing. But I think the colored buttons do NOT make it look like a child's toy and the colored controller looks rather tasteful in my opinion.
I hate it because the button prompts become useless in games (they will always show colored buttons).
Ripper_TV's comments