Colo. Rev. Stat. § 1-5-411
If the ballots to be furnished to any election judges are not delivered at the time and in the manner required in section 1-5-410 or if after delivery they are destroyed or stolen, it shall be the duty of the designated election official to cause other ballots to be prepared, as nearly in the form prescribed as practicable, with the words "substitute ballot" printed on each ballot. Upon receipt of the ballots thus prepared from the designated election official, accompanied by a statement under oath that the designated election official prepared and furnished the substitute ballots and that the original ballots have not been received or have been destroyed or stolen, the election judges shall cause the substitute ballots to be used at the election. If from any cause neither the official ballots nor the substitute ballots are ready in time to be distributed for the election or if the supply of ballots is exhausted before the polls are closed, unofficial ballots, printed or written, made as nearly as possible in the form of the official ballots, may be used until substitutes prepared by the designated election official can be printed and delivered.
C.R.S. § 1-5-411
This section is similar to former § 1-6-408 as it existed prior to 1992.