C.R.S. § 1-13-103

Any person violating any of the provisions of this code is a competent witness against any other violator and may be compelled to attend and testify at any trial, hearing, proceeding, or investigation in the same manner as other persons; but the testimony so given shall not be used in any prosecution or proceeding, civil or criminal, against the person so testifying, except for perjury in giving such testimony. A person so testifying shall not thereafter be liable to indictment, prosecution, or punishment for the offense with reference to which his testimony was given and may plead or prove the giving of testimony accordingly in bar of such indictment or prosecution.