Romney won college graduates and won White post-graduates, too.
I find that hard to believe, but I'd be interested in seeing the exit polls that show such. They'd be more interesting to look over than the same 4 categories you see everywhere else.
I'm having trouble finding ANY 2012 exit polls that aren't just simple tables (i.e., I can't find any of the ones that ask things like "Most Important Issue," "When you decided whom to vote for," etc.), but in 2014, Republicans won 57% of White College graduates and only 28% of non-White college graduates.
Also interesting to note that Republicans won 54% of Whites aged 18-29 but only won 42% of Whites aged 30-44. (Before you say this section looks unbelievable, I believe they mixed up the percentages for Black and Latino.)
http://www.nbcnews.com/politics/elections/2014/US/house/exitpoll