C.R.S. § 14-2-304

(1) The validity, enforceability, interpretation, and construction of a premarital agreement or marital agreement are determined: (a) By the law of the jurisdiction designated in the agreement if the jurisdiction has a significant relationship to the agreement or either party at the time the agreement was signed and the designated law is not contrary to section 14-2-309 or to a fundamental public policy of this state; or (b) Absent an effective designation described in paragraph (a) of this subsection (1), by the law of this state, including the choice-of-law rules of this state.