Legal window tint in Colorado comes down to two numbers: your windshield must let through at least 70% of visible light, and every other window must let through at least 27%.1Justia Law. Colorado Revised Statutes Title 42 Section 42-4-227 You can also run a non-transparent strip across the top of the windshield, but its bottom edge cannot drop more than four inches below the top of the glass, and it cannot be red or amber. Factory-tinted glass that met federal standards when the car was built is always legal, no matter what a meter reads today.
Why Your Film’s VLT Rating Isn’t Your Window’s VLT
The percentage printed on a roll of aftermarket film is the film’s rating by itself. It is not what an officer’s meter will read once the film is on your car. Factory glass already blocks some light on its own, typically transmitting around 70% to 82% depending on the vehicle. When you add film over that glass, the two percentages multiply.
Say your factory side glass transmits 80% of light and you install a film rated at 35%. The combined VLT is 0.80 × 0.35 = 0.28, or 28%. That barely clears Colorado’s 27% minimum, and depending on where an officer places the meter, the reading could land on either side of the line. The same 80% glass with a 30% film produces 24% VLT, which is illegal. Ask your installer to measure the factory glass first and run the math before you pick a film.
Rear Windows Can Be as Dark as You Want
Colorado lets any vehicle run rear windows darker than 27% VLT, as long as the windshield and the front side windows still meet their respective minimums.1Justia Law. Colorado Revised Statutes Title 42 Section 42-4-227 This isn’t limited to SUVs or vans. A sedan, a coupe, or a pickup can carry limo tint on the rear side windows and back glass.
If you do go dark in the back, Colorado requires functional side mirrors on both sides of the vehicle so you can still see traffic behind you. Most vehicles already have dual mirrors; if yours doesn’t, add the second one before you tint.
Reflectivity and Color Rules
Colorado bans any film that gives your windows a metallic or mirrored appearance, on any window, on any vehicle.1Justia Law. Colorado Revised Statutes Title 42 Section 42-4-227 It isn’t a “no more reflective than factory” standard. If your windows look chrome, they’re illegal, whatever the VLT reads.
The windshield strip has extra restrictions: no red, no amber, and nothing that distorts your perception of primary colors.1Justia Law. Colorado Revised Statutes Title 42 Section 42-4-227 Those colors can make traffic signals and emergency lights harder to read, which is the point of the rule.
Which Films Stay Compliant
Metallic films use metal particles to reflect heat and light. They give off the shiny look the statute bans, and they can also interfere with GPS, radio, and cell signals. Ceramic films use non-metallic particles that block heat without the reflective finish and without disrupting electronics. Ceramic costs more but is the cleanest match for Colorado’s reflectivity rule.
Dyed films are the cheapest option. They absorb light rather than reflect it, so they don’t run into the metallic-appearance ban. Heat rejection is weaker, and they can fade to purple over time. If you go that route, make sure the film still meets 27% VLT as it ages.
What a Tint Ticket Costs
Illegal window tint is a Class B traffic infraction in Colorado.1Justia Law. Colorado Revised Statutes Title 42 Section 42-4-227 The fine runs from $15 to $100, plus mandatory surcharges that fund victim compensation and witness assistance.2Justia Law. Colorado Revised Statutes Title 42 Section 42-4-1701 Even a low-end ticket ends up costing more than the base fine suggests once surcharges are added.
The citation itself is small. The real expense usually arrives later: stripping the illegal film and reinstalling compliant film typically runs $150 to $450 for a full vehicle, depending on how many windows you have and what film you choose. Some jurisdictions also treat unfixed tint as an ongoing issue that justifies additional stops.
How Officers Measure Your Tint
Officers use handheld VLT meters. The device sits on the edge of the glass, shines a light through, and reads what makes it to the sensor on the other side. These meters are accurate to plus or minus two percentage points, so a reading of 26% could represent actual VLT anywhere from 24% to 28%. Officers check their meters against reference standards before use to confirm they’re reading within tolerance.
An officer doesn’t always need a meter to pull you over. If your face shows only as a silhouette through the side glass, or your windows look visibly darker than the training samples the officer carries, that’s enough reasonable suspicion for a stop.
The two-point tolerance is why you want a buffer. A window measuring exactly 27% on your installer’s meter might read 25% on an officer’s. Aiming for 30% or higher on your front side windows gives you room against meter variance, slow film degradation, and the spot on the glass where the officer happens to place the device.
No Medical Exemption in Colorado
Several states let drivers with conditions like lupus or severe photosensitivity apply darker-than-legal tint with a doctor’s note. Colorado’s statute does not. Section 42-4-227 covers VLT limits, the windshield strip, reflectivity, law enforcement vehicles, and penalties, and it includes no physician-based waiver.1Justia Law. Colorado Revised Statutes Title 42 Section 42-4-227
If sunlight exposure is a medical problem for you, the options that stay within Colorado law are the darker rear-window allowance, UV-blocking clear or near-clear ceramic films on the front windows (some block more than 99% of UV while still meeting 27% VLT), and UV-protective clothing or sunglasses. You can ask the Colorado State Patrol or the DMV whether any administrative accommodation exists outside the statute, but don’t assume a doctor’s note will keep an officer from writing a ticket.
Commercial Vehicles Face a Stricter Standard
If you drive a commercial motor vehicle, federal rules sit on top of Colorado’s. The windshield and the two windows immediately to the left and right of the driver must transmit at least 70% of visible light.3eCFR. 49 CFR 393.60 – Glazing in Specified Openings That’s much tighter than Colorado’s 27% side-window rule, which means commercial drivers effectively can’t add tint to their front side windows at all beyond what the factory glass provides.
The federal 70% rule reaches only the windshield and those two driver-adjacent windows. Rear side windows and the back glass on a commercial vehicle still follow state law. All glazing on commercial vehicles built after December 25, 1968, also has to meet Federal Motor Vehicle Safety Standard No. 205.3eCFR. 49 CFR 393.60 – Glazing in Specified Openings
Buying a Used Car That’s Already Tinted
Dealers are generally expected to sell vehicles that comply with state equipment laws, but if the tint turns out to be illegal, you’re the one holding the ticket at the traffic stop, not the seller. Proving a dealership knowingly sold a car with non-compliant film is a steep burden, especially months after the sale.
Before you sign on a used car with aftermarket tint, ask the dealer to run a VLT meter on the windows or have it checked independently. If you find out after the fact, ask the dealership to remove or reimburse, but be ready to pay for it yourself if they refuse. Budget $150 to $450 for a full strip-and-replace with compliant film.