Colo. Rev. Stat. § 31-35-416
All revenue bonds and any coupons appertaining thereto relating to a water system, sewer system, or joint water and sewer system issued or purportedly issued prior to March 13, 1962, and all acts and proceedings had or taken or purportedly had or taken prior to said date by or on behalf of municipalities, under law or under color of law, preliminary to and in the authorization, execution, sale, and issuance of all water revenue bonds, sewer revenue bonds, and joint water and sewer revenue bonds, including any coupons appertaining thereto, the authorization and execution of all other contracts, and the exercise of other powers in this part 4 are validated, ratified, approved, and confirmed by this section except as provided in section 31-35-417, notwithstanding any lack of power, authority, or otherwise, other than constitutional, and notwithstanding any defects and irregularities, other than constitutional, in such securities, acts, and proceedings, in such authorization, execution, sale, and issuance, and in such exercise of powers; and such securities and other contracts are and shall be binding, legal, valid, and enforceable obligations of such municipality to which they appertain in accordance with their terms and their authorization proceedings.
C.R.S. § 31-35-416
This section is similar to former § 31-35-416 as it existed prior to 1975.