If I have a concealed carry permit, can I carry on college school grounds? YES (with conditions, and as long as it is a public school)
18-12-105.5. Unlawfully carrying a weapon - unlawful possession of weapons - school, college, or university grounds.
(3) It shall not be an offense under this section if:
(d) The person, at the time of carrying a concealed weapon, held a valid written permit to carry a concealed weapon
However, then Attorney General Ken Salazar wrote an opinion that, since the Regents to the University of Colorado are a constitutional office and have powers to govern that university, they may ban concealed carry on their campuses. As of the writing of this document, all of CU's campuses have a ban on concealed carry.