Howdy Friend,
First, welcome to a truly OC friendly state (with the exception of the people's republic of Denver city/county).
Any private property open to the public; i.e. stores, malls, etc) must have clearly displayed signs to that affect at all entrances to their business.
Aside from that, you should have absolutely no problem OC'ing anywhere in Colorado.
Without a valid CCW recognized by Colorado, you don't want to be within 1,000 feet of a school when on foot or such, but that's pretty universal throughout the states.
My advice would be to relax, go about your normal law abiding business and don't concern yourself much about OC'ing. Odds are that few will even notice. Of those that do, many will simply assume you are a cop or otherwise authorized to openly carry a firearm. In fact, you are otherwise authorized as stipulated in our Colorado Constitution; Article 2, sections 3 and 13. Very strong language to support your right to carry without a permit.
Anyhow, As they say in the Nike commercials... Just do it!
Blessings,
M-Taliesin