Colo. Rev. Stat. § 1-13.5-904
In local government elections in which paper ballots are used, the designated election official shall cause to be printed or copied and distributed to the election judges in each respective polling place a sufficient number of ballots. The ballots shall be sent in one or more sealed packages for each polling place, with marks on the outside of each clearly stating the polling place for which it is intended and the number of ballots enclosed. The packages must be delivered to one of the election judges of each polling place no later than the day before the election. The election judge who receives the ballots thus delivered shall give receipt for them, which receipt must be filed with the designated election official, who shall also keep a record of the time and manner in which each of said packages was sent and delivered. The election judge receiving the package shall produce the same, with the seal unbroken, in the proper polling place at the opening of the polls on election day and, in the presence of all election judges for the polling place, shall open the package.
C.R.S. § 1-13.5-904