Colorado has been going blue and Libertarian for some time. It stuck its finger at the hapless CRP (which looked like The Keystone Cops) in 2010 and elected the Socialist Mayor of Denver, John Hickenlooper, as Governor over Independent Tom Tancredo. Tancredo lost badly in part because he had no money and in part because he had come out publicly in the spring for legalizing marijuana, a "no no" for a candidate trying to get Republican and Conservative support.
Democrats won Congressional seats that year in Colorado when there was a tremendous shift nearly everywhere else to the right.
Romney avoided military service which doesn't help him with veterans and military folks in Colorado and as a neocon, he certainly isn't going to get the Libertarian vote.
One other thing: The Democrat Party is much better organized in Colorado than the CRP.