Thinking about underglow for your car in Washington? Here is what the law says, and how to run it legally. Ready to install? See our RGBIC underglow kit and the install guide.

Is Underglow Legal in Washington? (2026 Guide)

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

Underglow rules in Washington

• Not road-legal: Washington allows underglow only when parked on private property; it is not permitted while driving on public roads.
• Colors: Red to the front is reserved for enumerated vehicles and blue for law enforcement. Even on private property, no red or blue and no flashing, practically only white or amber.
• Driving vs parked: Private-property, parked use only, still subject to color limits.

Underglow while parked or on private property

Because Washington 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, and those road rules generally do not reach private property. 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 motion. Keep to compliant colors and check local ordinances.

How to stay legal with underglow in Washington

• 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

Revised Code of Washington 46.37.210 and WAC 204-21 (lighting equipment), verified against the official Washington Legislature site. You can read the referenced law here: Washington statute.

Ready to install?

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

Washington Underglow FAQ

Is underglow legal in Washington?
Underglow is not permitted while driving on public roads; allowed only when parked on private property. Keep the lights steady, show no red to the front, and avoid blue.

What underglow colors are illegal in Washington?
No red to the front and no blue; even parked, no red or blue and no flashing (practically white or amber only). Flashing or strobing of any color is not allowed.

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.