Colo. Rev. Stat. § 31-30-202
Immediately upon the adoption of the merit system under civil service regulations, the governing body shall appoint three persons as civil service commissioners who shall be known and designated as the board of civil service commissioners or board of public safety to serve for six years, four years, and two years, respectively, from the date of their appointment and until their successors are appointed and qualified. Every alternate year the governing body shall appoint one person, as the successor of the commissioner whose term shall expire, to serve for the term of six years from the date of the appointment and until a successor is appointed and qualified. Any vacancy may be filled for the unexpired term by appointment by the governing body. At no time shall more than two commissioners be members of the same political party. Said commissioners shall serve without compensation but shall be paid their necessary expenses actually incurred in the discharge of their official duties.
C.R.S. § 31-30-202
This section is similar to former § 31-30-202 as it existed prior to 1975.