Colo. Rev. Stat. § 32-9-123
If the taxes levied are not paid, then delinquent real property shall be sold at the regular tax sale for the payment of said taxes, interest, and penalties, in the manner provided by the statutes of the state for selling real property for the nonpayment of taxes. If there are no bids at said tax sale for the property so offered, said property shall be struck off to the county, and the county shall account to the district in the same manner as provided by law for accounting for school, town, and city taxes. Delinquent personal property shall be distrained and sold as provided by law. Nothing in this article shall be construed as preventing the collection in full of the proceeds of all levies of taxes lawfully made by the district, including without limitation any delinquencies, interest, penalties, and costs.
C.R.S. § 32-9-123
For the sale of tax liens, see article 11 of title 39.