Colo. Rev. Stat. § 15-12-701
The duties and powers of a personal representative commence upon his or her appointment. The powers of a personal representative relate back in time to give acts by the person appointed that are beneficial to the estate occurring prior to appointment the same effect as those occurring thereafter. Prior to appointment, a person nominated to serve as personal representative in a will may carry out written instructions of the decedent or of the persons designated to control disposition of the decedent's last remains under section 15-19-106, relating to his or her body, anatomical gifts, funeral, and burial arrangements. A personal representative may ratify and accept acts on behalf of the estate done by others where the acts would have been proper for a personal representative.
C.R.S. § 15-12-701