Colo. Rev. Stat. § 31-30-102
The governing body of any city or town in the state maintaining a paid police department, a paid fire department, or a paid street department may establish a commission which shall be known as "the city (town) of .... fire and police and street department civil service commission". Said governing body shall not have the authority to withdraw said departments from operation of such system unless and until the withdrawal thereof has been submitted to the registered electors of said city or town at a special or regular election held in said city or town pursuant to an ordinance properly passed submitting the same to said electors and has been approved by not less than a majority vote of said electors voting on such proposition.
C.R.S. § 31-30-102
This section is similar to former § 31-30-102 as it existed prior to 1975.