Colo. Const. art. V, § 3

Terms of senators and representatives. (1) Senators shall be elected for the term of four years and representatives for the term of two years. (2) In order to broaden the opportunities for public service and to assure that the general assembly is representative of Colorado citizens, no senator shall serve more than two consecutive terms in the senate, and no representative shall serve more than four consecutive terms in the house of representatives. This limitation on the number of terms shall apply to terms of office beginning on or after January 1, 1991. Any person appointed or elected to fill a vacancy in the general assembly and who serves at least one-half of a term of office shall be considered to have served a term in that office for purposes of this subsection (2). Terms are considered consecutive unless they are at least four years apart.