Colo. Rev. Stat. § 30-15-406
No ordinance shall be adopted by any board of county commissioners of any county in this state unless the same has been previously introduced and read at a preceding regular or special meeting of such board and published in full in one newspaper of general circulation published in such county at least ten days before its adoption. If there is no such newspaper published in the county, copies of the proposed ordinance shall be posted in at least six public places in such county at least ten days prior to its adoption. Such previous introduction of such ordinance at such preceding meeting of the board of county commissioners and the fact of its publication in such newspapers or by posting shall appear in the certificate and the attestation of the county clerk and recorder on such ordinance after its adoption.
C.R.S. § 30-15-406