C.R.S. § 13-62.1-106

(1) A person may assert a claim in a specified foreign money. If a foreign-money claim is not asserted, the claimant makes the claim in United States dollars. (2) An opposing party may allege and prove that a claim, in whole or in part, is in a different money than that asserted by the claimant. (3) A person may assert a defense, set-off, recoupment, or counterclaim in any money without regard to the money of other claims. (4) The determination of the proper money of the claim is a question of law.