That is a lot of words that do not say much.
Colorado law is pretty clear. If you offer a service to the public, you can not choose which protected classes to offer that service to. You can talk all you want about contracts and tomorrow, but that does not change the law. 

By the way, the baker agreed in writing to abide by state law when he signed his business application. He went back on his word. Lying is a bigger sin than making a cake for a gay wedding.