Colorado Revised Statutes Title 40. Utilities § 40-6-124. Disqualification

(a) Have a personal bias or prejudice concerning a party;

(b) Have served as an attorney or other representative of any party concerning the matter at issue, or were previously associated with an attorney who served, during such association, as an attorney or other representative of any party concerning the matter at issue;

(c) Know that they or any member of their family, individually or as a fiduciary, has a financial interest in the subject matter at issue, is a party to the proceeding, or otherwise has any interest that could be substantially affected by the outcome of the proceeding; or

(d) Have engaged in conduct which conflicts with their duty to avoid the appearance of impropriety or of conflict of interest.