Thinking about adding underglow to your car? Here is what Illinois law says, and how to run it legally. If you are ready to install, see our RGBIC underglow kit and the step-by-step install guide.

Is Underglow Legal in Illinois? (2026 Guide)

Short answer: Underglow is not permitted on public roads in Illinois. Only expressly authorized lighting is allowed, and underglow is not authorized. Off-road and show use is the safe use.

Two rules are nearly universal across the US: no red light shown to the front and no blue underglow (both are reserved for emergency vehicles), and no flashing, rotating, or strobing lights while driving. Beyond that, states differ. Here is how Illinois handles it.

Underglow rules in Illinois

Not authorized: Illinois prohibits any lighting not expressly permitted by its Vehicle Code. Undercarriage underglow is not among the permitted placements, so it cannot be illuminated while driving on a highway.
Colors: No red light visible from directly in front. Red and blue especially risk an additional emergency-impersonation charge.
No flashing: Flashing, oscillating, and rotating lights are prohibited except for authorized signals and hazards.
Driving vs parked: Not permitted while driving on public highways. Off-street and private-property use is the safe option.

Underglow while parked or on private property

Because Illinois does not permit lit underglow on public roads, genuinely private property, a private lot, driveway, car show, or off-road, is the practical place to enjoy it. Those road rules are written around vehicles on a public highway, so private property is generally outside them. Be aware that a car parked on a public street is usually still treated as being on the highway, and red or blue lighting can trigger separate police-impersonation laws regardless of whether the car is moving. Keep to compliant colors and check your local ordinances.

How to stay legal with underglow in Illinois

Keep the lights steady-burning, never flashing, strobing, or rotating.
Show no red light to the front, and avoid blue entirely.
Do not mimic emergency-vehicle lighting or obscure your license plate.
Confirm the current rule below and check locally before driving with it on.

The law

625 ILCS 5/12-212 (additional lighting equipment) provides that lighting not expressly authorized is prohibited, confirmed via the Illinois General Assembly and FindLaw. Related: 625 ILCS 5/12-215 (oscillating, rotating, and flashing lights). You can read the referenced law here: Illinois statute.

Please note: This page is general information, not legal advice. Underglow laws change and enforcement varies by locality and officer. Confirm the current Illinois statute and check with local law enforcement or your DMV before installing or driving with underglow.

Ready to install?

Our RGBIC underglow kit lets you dial in any color and keep it steady, and the install guide walks through wiring it to a switched power source. Free shipping on all US orders.

Illinois Underglow FAQ

Is underglow legal to drive with in Illinois?
No. Illinois only authorizes specific lighting, and underglow is not on that list, so it cannot be lit while driving on public highways.

Can I use underglow off the road in Illinois?
Yes. Private-property and show use is the safe option. It is on-road illuminated use that is prohibited.

Can I have underglow on while parked in a lot?
On genuinely private property, such as a private lot, driveway, or car show, underglow use is generally far less restricted. On a public street a parked car is usually still treated as being on the highway, so the color rules still apply, avoid red and blue, and check your local ordinances.

Updated July 2026.