Section 18-1-504 - Effect of ignorance or mistake upon culpability(1) A person is not relieved of criminal liability for conduct because he engaged in that conduct under a mistaken belief of fact, unless: (a) It negatives the existence of a particular mental state essential to commission of the offense; or(b) The statute defining the offense or a statute relating thereto expressly provides that a factual mistake or the mental state resulting therefrom constitutes a defense or exemption; or(c) The factual mistake or the mental state resulting therefrom is of a kind that supports a defense of justification as defined in sections 18-1-701 to 18-1-707.(2) A person is not relieved of criminal liability for conduct because he engages in that conduct under a mistaken belief that it does not, as a matter of law, constitute an offense, unless the conduct is permitted by one or more of the following: (a) A statute or ordinance binding in this state;(b) An administrative regulation, order, or grant of permission by a body or official authorized and empowered to make such order or grant the permission under the laws of the state of Colorado;(c) An official written interpretation of the statute or law relating to the offense, made or issued by a public servant, agency, or body legally charged or empowered with the responsibility of administering, enforcing, or interpreting a statute, ordinance, regulation, order, or law. If such interpretation is by judicial decision, it must be binding in the state of Colorado.(3) Any defense authorized by this section is an affirmative defense.L. 71: R&RE, p. 404, § 1. C.R.S. 1963: § 40-1-604. For other provisions concerning affirmative defenses generally, see §§ 18-1-407, 18-1-710, and 18-1-805; for affirmative defenses to particular crimes, see specific criminal provisions in articles 2 through 18 of this title 18.