Colorado Window Tint: 27% on Every Window but the Windshield

Most states publish a table with one number for the front side windows, another for the rear sides and a third for the back glass. Colorado does not. Section 42-4-227 (1)(a)(I) states one figure, twenty-seven percent light transmittance, and applies it to "any window, except the windshield" on a motor vehicle registered in Colorado. The windshield gets its own floor of seventy percent. Because the rule is written as a single threshold rather than a table, a film that measures 27 percent or better is compliant on the driver's window, the passenger window, the rear side windows and the back glass alike.

The one relaxation is at subparagraph (II). Windows to the rear of the driver, including the rear window, may fall below twenty-seven percent, but the trade is explicit: the front side windows and the windshield on that vehicle must allow at least seventy percent light transmittance. That is a much stricter front-glass standard than the 27 percent baseline, so a Colorado driver who wants limousine glass in the back cannot also run film on the front doors. It is one or the other.

A separate allowance at § 42-4-227 (1)(b) governs the windshield strip. Nontransparent material may be applied to the topmost portion of the windshield if the bottom edge of the material extends no more than four inches measured from the top of the windshield down, if the material is not red or amber in color and does not distort perception of primary colors or contain vision-obstructing lettering, and if it does not reflect sunlight or headlight glare into oncoming or preceding drivers any more than the bare windshield would. Four inches is the whole allowance; Colorado does not use the AS-1 line that several neighboring states rely on.

Two absolute bars sit alongside the numbers. Subsection (1)(d) says no material presenting a metallic or mirrored appearance may be used on any window in the motor vehicle, which rules out chrome and mirror films at every transmittance level, and "metallic or mirrored appearance" is also written into the 27 percent test itself at (1)(a)(I). Subsection (1)(c) preserves factory glazing that was approved by federal statute or regulation and installed when the vehicle was manufactured, along with a like-for-like replacement of that glass. Subsection (1)(e) preserves registration certificates and similar papers that do not obstruct the driver's view.

Read the exceptions as a closed list, because that is what the section gives you. The only vehicle-class exception is at (1)(a)(III) for a law enforcement vehicle owned or leased by a state or local law enforcement agency, and even that carries a condition: a police vehicle tinted below 27 percent "shall not be used for any traffic law enforcement operations". There is no medical or photosensitivity exemption anywhere in § 42-4-227, and no permit, waiver or physician-certificate procedure elsewhere in part 2 of article 4 of title 42. A Colorado driver with a light-sensitivity diagnosis has no statutory route to darker front glass.

Enforcement is roadside, because Colorado runs no periodic safety inspection. The only recurring inspection in title 42 is the emissions certificate required in the program area defined at C.R.S. § 42-4-304 (20), which covers Adams, Arapahoe, Boulder, Douglas, El Paso, Jefferson, Larimer and Weld counties plus the cities and counties of Broomfield and Denver, with named rural exclusions in Adams, Arapahoe, El Paso, Larimer and Weld. That is an emissions test, not an equipment test, and it never reaches window film. The provision that does is § 42-4-203 (1), which lets a uniformed police officer, at any time upon reasonable cause, require a driver to stop and submit the vehicle and its equipment to an inspection "and such test with reference thereto as may be appropriate". That is the authority behind a tint meter at the curb. The same subsection adds that the fact a vehicle is an older model shall not alone constitute reasonable cause.

A driver who operates a vehicle whose glass fails § 42-4-227 (1)(a) commits a class B traffic infraction under subsection (3)(a). The shop or individual who applied the film is treated more seriously: subsection (3)(b) makes any person who installs, covers or treats a windshield or window so that it fails subsection (1)(a) guilty of a class A traffic infraction. § 42-4-1701 (4)(a)(I)(D) lists § 42-4-227 at a $50 penalty plus a $16 surcharge, which is more than triple the $15 and $6 assessed for most equipment sections in that same table.

On entry of judgment rather than payment of the assessment, § 42-4-1701 (3)(a)(I) sets a $15 minimum and $100 maximum penalty for both class A and class B traffic infractions. A traffic infraction in Colorado is a civil matter, so there is no jail exposure for tint, but the installer count means a citation can follow the film back to the business that sold it.