Colo. Rev. Stat. § 37-50-116
All assessments on account of special improvements against appraised benefits and interest thereon and penalties for default of payment thereof, together with the cost of collecting the same, from the date of the filing of the construction fund and the assessment record in the office of the treasurer of the county in which the lands and property are situated, shall constitute a perpetual lien in an amount not in excess of the benefits severally appraised upon the land and other property against which assessments have been levied and such benefits appraised. No sale of the property to enforce any general state, county, city, town, or school tax or other lien shall extinguish the perpetual lien of the assessment. At any time, a landowner may pay the full amount of the assessment, and thereafter the property of the landowner shall be clear and free from lien and shall not be subject to assessment for and on account of benefits appraised against any other land or default in the payment of assessments made against any other land.
C.R.S. § 37-50-116