Any person who installs, covers, or treats a windshield or window so that the windshield or window does not meet the requirements of paragraph (a) of subsection (1) of this section is guilty of a misdemeanor and shall be punished by a fine of not less than five hundred dollars nor more than five thousand dollars.
and here is that paragraph
(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.
so i am going to guess 675