Colo. Rev. Stat. § 25-8.5-113
Any revenue bonds issued by the authority may be refunded by the authority, or by any successor thereof, in the name of the authority, subject to the provisions concerning their payment and to any other contractual limitations in the proceedings authorizing their issuance or otherwise appertaining thereto, by the issuance of bonds to refund, pay, and discharge all or any part of such outstanding bonds, including any interest on the bonds in arrears or about to become due, for the purpose of avoiding or terminating any default in the payment of the interest on and principal of the bonds, of reducing interest costs or effecting other economies, or of modifying or eliminating restrictive contractual limitations appertaining to the issuance of additional bonds or to any system appertaining thereto or for any combination of such purposes. Refunding bonds may be delivered in exchange for the outstanding bonds refunded or may be sold as provided in this article for an original issue of bonds.
C.R.S. § 25-8.5-113