My current iMac is silver on the front with black bezels and the back is dust colored. Honestly, I don't really care what color they paint the back. I'm not staring at it all day. I'd rather it not be pink, but I wouldn't make a fuss over it.
White bezels on the other hand is putting the wrong color right where I'd have to see it all day every day. I'll be honest, I'd still get one. I'd just be one of those weirdos who spends thousands of something they don't like, then complains to everyone until I've chased off the few friends I have left.
However, my gut says they won't do white bezels. And that there will be decent colors to choose from. I'm not worried to be honest.