Colo. Rev. Stat. § 42-4-104
The department of transportation shall adopt a manual and specifications for a uniform system of traffic control devices consistent with the provisions of this article for use upon highways within this state. Such uniform system shall correlate with and insofar as possible conform to the system set forth in the most recent edition of the "Manual on Uniform Traffic Control Devices for Streets and Highways" and other related standards issued or endorsed by the federal highway administrator. For compliance with this section, the said department shall either publish and distribute a state manual and specifications approved by the transportation commission or shall, by the issuance of a traffic control manual supplement approved by the transportation commission, adopt the said national manual and other related standards subject to such exceptions, additions, and adaptations as are necessary for lawful and uniform application in this state. Said state manual or supplement shall be made available to all municipal and county road authorities and to other concerned agencies in the state.
C.R.S. § 42-4-104
This section is similar to former § 42-4-501 as it existed prior to 1994.