Colo. Rev. Stat. § 32-4-547
This part 5 shall operate to supply such legislative authority as may be necessary to validate any securities issued, other contracts executed by districts, and any acts and proceedings taken prior to February 12, 1962, appertaining to the issuance of securities or execution of other contracts by districts or otherwise, which the legislature could have supplied or provided for in the law under which such securities were issued, or such other contracts were executed and such acts or proceedings were taken; but this part 5 shall be limited to the validation of securities, other contracts, acts, and proceedings to the extent to which the same can be effectuated under the state and federal constitutions. This part 5, shall not operate to validate, ratify, approve, confirm, or legalize any bond or other security, other contract, act, proceedings, or other matter the legality of which is being contested or inquired into in any legal proceedings pending and undetermined on February 12, 1962, and shall not operate to confirm, validate, or legalize any bond or other security, other contract, act, proceedings, or other matter which has been determined in any legal proceedings to be illegal, void, or ineffective prior to February 12, 1962.
C.R.S. § 32-4-547