OP, your link is chock full of misinformation. It assumes that the only way to carry is concealed, which is false.
Open carry is allowed everywhere here except in Denver. some municipalities do prohibit certain city-controlled property against carrying, but they have to be posted. Private property signs don't carry the force of law, unless there are electronic screening devices and security personnel.
OC is fine, resident or not. But, as you noted, your CA permit won't allow you to legally carry concealed here in Colorado. But most jurisdictions are fine with it (again, the prominent exception is Denver). Some police officers may not like it, and may give you a hard time. I have never had such an experience in the past two years of open carrying.
What area are you visiting? If I have a more precise idea of the location, I might be able to provide more info. I have friends and coworkers all over the state.