Colo. Rev. Stat. § 36-5-106
Payment for the lands shall in all cases be made as provided for by law; but, if the person upon whose application said lands are offered for sale is the successful bidder, then, and not otherwise, the following terms for payment shall apply: The sum bid, or any part thereof, shall not be due until twenty years from the date of said sale, when it shall be paid in full. All or any portion of the sum bid may be payable at any semiannual period. All sums bid shall bear interest at six percent per annum until paid. The interest shall be due and payable annually. Payment of the first three payments of said interest shall be deferrable at the option of such purchasing applicant until the end of the third year. The state board of land commissioners has the power, but shall be under no obligation, to grant other extensions of time for the payment of interest, and all such overdue interest shall draw interest at six percent until paid. The expenses of such sale shall in all cases be paid by the applicant.
C.R.S. § 36-5-106
For terms of payment on the sale of state lands, see § 36-5-112.