C.R.S. § 39-1-117

Nothing in articles 1 to 13 of this title shall apply to or in any manner affect any valuation, assessment, allocation, levy, tax certificate, tax warrant, tax sale, tax deed, right, claim, demand, lien, indictment, information, warrant, prosecution, defense, trial, cause of action, motion, appeal, judgment, sentence, or other authorized act, done or to be done, or proceeding arising under or pursuant to the laws in effect immediately prior to August 1, 1964, but the same shall be governed by and conducted pursuant to the provisions of law in effect immediately prior to August 1, 1964.