Unless displaced by the particular provisions of this article, the "Uniform Commercial Code" and the principles of law and equity, including the law relative to capacity to contract, principal and agent, estoppel, fraud, misrepresentation, duress, coercion, mistake, bankruptcy, or other validating or invalidating cause, supplement the provisions of this article.
C.R.S. § 5-10-105
For the "Uniform Commercial Code", see title 4.