C.R.S. § 19-5-214

(1) No final decree of adoption shall be attacked by reason of any jurisdictional or procedural defect after the expiration of ninety-one days following the entry of the final decree; except that, in cases of stepparent adoption, no final decree of adoption shall be attacked by reason of fraud upon the court or fraud upon a party, whether or not there is a jurisdictional or procedural defect, after the expiration of one year following the entry of the final decree of adoption. (2) When a final decree of adoption is attacked on any basis at any time, the court shall consider the best interests of the child, taking into account the factors set forth in section 14-10-124 , C.R.S. The court shall sustain the decree unless there is clear and convincing evidence that the decree is not in the best interests of the child.