C.R.S. § 15-11-213

(1) Any affirmation, modification, or waiver of a marital right or obligation, as defined in section 14-2-302 , C.R.S., made on or after July 1, 2014, is unenforceable unless the affirmation, modification, or waiver is contained in a premarital or marital agreement, as defined in section 14-2-302 , C.R.S., that is enforceable under part 3 of article 2 of title 14 , C.R.S. (2) Any affirmation, modification, or waiver of a marital right or obligation made before July 1, 2014, is governed by the law in effect at the time the affirmation, modification, or waiver was made.