Colo. Rev. Stat. § 32-7-125
Any general obligation bonds issued by any service authority may be refunded without an election by the service authority issuing them, or by any successor thereof, in the name of the service authority which issued the bonds being refunded, but subject to 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 said bonds in arrears or about to become due, and for the purpose of avoiding or terminating any default in the payment of interest on and principal of said bonds, reducing interest costs or effecting other economies, or modifying or eliminating restrictive contractual limitations appertaining to the issuance of additional bonds or to any system appertaining thereto or for any combination of the foregoing 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. § 32-7-125