Colo. Const. art. XIV, § 2

Removal of county seats. The general assembly shall have no power to remove the county seat of any county, but the removal of county seats shall be provided for by general law, and no county seat shall be removed unless a majority of the registered electors of the county, voting on the proposition at a general election vote therefor; and no such proposition shall be submitted oftener than once in four years, and no person shall vote on such proposition who shall not have resided in the county six months and in the election precinct ninety days next preceding such election.