Colorado Revised Statutes Title 42. Vehicles and Traffic § 42-4-227. Windows unobstructed--certain materials prohibited--windshield wiper requirements

(1)(a)(I) Except as otherwise provided in this paragraph (a), no person shall operate a motor vehicle registered in Colorado on which any window, except the windshield, is composed of, covered by, or treated with any material or component that presents an opaque, nontransparent, or metallic or mirrored appearance in such a way that it allows less than twenty-seven percent light transmittance. The windshield shall allow at least seventy percent light transmittance.

(II) Notwithstanding subparagraph (I) of this paragraph (a), the windows to the rear of the driver, including the rear window, may allow less than twenty-seven percent light transmittance if the front side windows and the windshield on such vehicles allow at least seventy percent light transmittance.

(III) A law enforcement vehicle may have its windows, except the windshield, treated in such a manner so as to allow less than twenty-seven percent light transmittance only for the purpose of providing a valid law enforcement service. A law enforcement vehicle with such window treatment shall not be used for any traffic law enforcement operations, including operations concerning any offense in this article. For purposes of this subparagraph (III), “law enforcement vehicle” means a vehicle owned or leased by a state or local law enforcement agency. The treatment of the windshield of a law enforcement vehicle is subject to the limits described in paragraph (b) of this subsection (1).

(I) The bottom edge of the material extends no more than four inches measured from the top of the windshield down;

(II) The material is not red or amber in color, nor does it affect perception of primary colors or otherwise distort vision or contain lettering that distorts or obstructs vision;

(III) The material does not reflect sunlight or headlight glare into the eyes of occupants of oncoming or preceding vehicles to any greater extent than the windshield without the material.