Open carry is legal in Colorado but I have some reservations about it with the current legal climate. One of the things we’ve seen happen around the country is that when carrying open in places like Walmart or the grocery store we’re seeing criminals take guns from people and then the DA or the local jurisdiction charge that gun owner with negligence when he loses the gun to the criminal. Of course, carrying in an open space like the mountains or a river trail or some walking trail is generally accepted practice. Colorado has some areas that it’s illegal to carry open and you can be arrested namely Denver and Denver County. It is not true that open carry deters crime. It is just the opposite. Open carry attracts crime to you and makes you a target both for police and criminals. It tends to make the public nervous and attracts too much attention to the open carrier.
See the Colorado Do’s and Don’ts, A White Paper outlining important aspects of traveling with a gun in Colorado