Colo. Rev. Stat. § 39-12-101
No action for the recovery of land for which a tax deed was issued under the provisions of article 11 of this title for delinquent taxes shall lie unless the same is brought within five years after the execution and delivery of the deed therefor by the treasurer, any laws to the contrary notwithstanding; except that, when any owner of such land, for which a tax deed has been issued, at the time of the execution and delivery of the deed by the treasurer is under legal disability, it shall be lawful for him to bring a suit or action for the recovery of the land within the period during which he has the right to make redemption of such land from the tax sale upon which the deed is based. When a recovery of any of such land is effected in any suit, action, or proceeding, the value of all improvements made in good faith on such lands, and all sums paid for the tax lien on said land and for improvements, and all costs incident to the issuance and recording of the treasurer's deed, and all taxes and assessments paid thereon after the sale of the tax lien thereof, including the redemption value of all tax sale certificates redeemed, held, or surrendered for redemption by the grantee in such treasurer's deed or his heirs or assigns, shall be ascertained by the court or jury trying the action for recovery and shall be paid, together with interest thereon at the rate of twelve percent per annum, by the person recovering said land to the persons entitled thereto, and the payment of such sum shall be a condition precedent to the entry of judgment or decree in such suit, action, or proceeding. All such treasurer's deeds executed by the treasurer purporting to convey lands and improvements thereon for all purposes shall be deemed to be color of title from and after the time the same is recorded in the office of the county clerk and recorder for the county in which said lands are located. The term "improvements" includes sums and amounts of money expended thereon in good faith by the grantee and his successors and assigns in search of minerals and oil, as well as other expenditures for the improvements of such lands which add to the cost and value thereof.
C.R.S. § 39-12-101
For limitation of actions with respect to persons under disability, see article 81 of title 13.