Colo. Rev. Stat. § 13-93-107
It is unlawful for judges of the district, county, and municipal courts to counsel or advise in or write any petition or answer or other pleadings in any proceeding, or to perform any service as attorney- or counselor-at-law, or to be interested in any profits or emoluments arising out of any practice in any of said courts, except costs in their own courts; except that county judges in counties of such classes as may be specified by the laws relating to county courts, if licensed attorneys, may practice in courts other than the county court and in matters that have not come before the county court; and further, municipal judges, if licensed attorneys, may practice in courts other than the municipal court and in matters that have not come before the municipal court.
C.R.S. § 13-93-107
This section is similar to former § 12-5-110 as it existed prior to 2017.