Colorado law allows certain convicted felons to own or possess guns.
Federal law still makes it a crime to do so, and in some cases the feds have pursued prosecution of those who possess guns in states that allow it. Only an attorney should advise you on this matter but the basics of Colorado’s laws are as follows:
Until 1994: Colorado felons who completed their sentences prior to 1984 were allowed to wait 10 years and then file an application with the state to have their right to own/possess firearms reinstated.
However, in 1994, the state passed a new law and since then it has been illegal for anyone ever convicted of a felony to ever own a weapon. Those who were already restored got to keep their guns, but anyone who did not meet the 10 year mark by the time the new law went into effect was out of luck.
Recently, Colorado has been toying with the idea of allowing certain felons, (primarily those convicted of non-violent crimes) to have their firearms rights restored if they wished to own/possess guns for the sole purpose of defending their homes or families.
Final thoughts: Until such laws are passed a felon’s only way to once again be allowed to own/possess a firearm is through a governor office full pardon. Even then, you are still in violation of the federal felon and gun laws, therefore, should speak to an attorney to determine whether the expense and time to get a pardon is worth the effort.