You’ve seen those cars glowing under the body at night. They look cool. Maybe you want that look for your own vehicle. But before you buy anything, you need to know the rules in Washington state.
This article breaks down exactly what’s legal, what’s not, and what could cost you money.
What Is Underglow?
Underglow is lighting placed underneath a vehicle. It sits below the car’s body and shines down toward the road. The glow creates a colored light effect around the bottom of the vehicle.
People use two main types. Neon tubes were popular first. LED strips are more common now because they last longer and are tougher. Either way, the laws treat them the same in Washington.
Is Underglow Legal in Washington State?
Okay, this part is important. Underglow is illegal on public roads in Washington state. That’s the short answer. It doesn’t matter if your lights are neon or LED. If you’re driving on a public street, highway, or road, you cannot have underglow on.
Washington is one of only nine states in the country that bans underglow on public roads outright. Most states allow it with some restrictions. Washington takes a stricter approach.
Wondering if there’s any situation where it’s allowed? Actually, yes. There is one exception.
When Is Underglow Allowed?
You can use underglow if your vehicle is parked on private property and not moving. That’s it. Think of a car show in a private parking lot. Or showing off your car in your own driveway. That’s where underglow is okay.
But even then, there are rules you must follow. Your lights cannot be red or blue. Those colors are reserved for emergency vehicles and police. Your lights also cannot flash or rotate. They must be steady and still.
So basically, if you’re parked privately with calm, non-red, non-blue lights, you’re in the clear.
The Law Behind It All
Washington’s underglow rules come from the Washington Administrative Code. Specifically, WAC 204-21-230 covers prohibited lighting equipment. This section was last updated in March 2026 and went into effect on April 25, 2026.
The law says that if a vehicle is moving on a public roadway, it cannot display aftermarket lighting. Period. The law also bans specific colors for all vehicles on the road, moving or not.
This isn’t a new rule. Washington has restricted aftermarket vehicle lighting for years. The 2026 update clarified and reinforced those restrictions.
Colors That Are Always Banned
Hold on, this part is important. Even when parked on private property, certain colors are completely off-limits. You need to know these before buying any light kit.
Red lights are prohibited on any regular vehicle. Only emergency vehicles, police, school buses, and emergency tow trucks can display red. Blue lights are only for law enforcement vehicles. Flashing white lights are banned for regular vehicles too. Green lights are only allowed for firefighters’ private vehicles under a specific law.
Most people don’t realize how strict the color rules are. You’re not alone if this surprises you.
What About LED Rock Lights?
This one comes up a lot. Rock lights are small lights placed in wheel wells. Offroad drivers use them to see the ground while driving trails at night.
Washington law specifically mentions aftermarket neon lighting devices on public roads. Rock lights and underglow used only off-road or on private property fall into a gray area. Most legal experts say if you’re on public pavement, any underglow-style lighting is a problem.
Honestly, this is the part most people miss. The law targets on-road use. Use your judgment. If you only light up while mudding on private land, you’re likely fine. Drive home with those lights on, and you’re not.
The Penalties
So what happens if you break this law? You could face a fine of $124. That’s the standard penalty for violating vehicle lighting regulations in Washington.
Think of it like a seatbelt ticket. It’s not a massive fine, but it goes on your record. Officers can also pull you over for the violation alone. And once you’re pulled over, they can look for other issues too.
Washington State Patrol officers are known for strict enforcement. Don’t be surprised if a trooper notices your underglow and uses it as a reason to stop you.
Can Local Cities Add More Rules?
Yes, they can. Washington state law sets the minimum standard. But cities and counties can add their own rules on top of that. Seattle, Spokane, Tacoma, and other cities may have local lighting rules that are even stricter.
If you’re unsure about your city, check with your local police department or city code office. It takes about five minutes and could save you a headache.
How to Enjoy Underglow Without Breaking the Law
You’re not completely out of luck here. You can still enjoy underglow. You just have to be smart about it.
Install your lights, but use a switch. Turn them off before you leave private property. Never drive on public roads with them on. Keep the colors legal. No red, no blue, no flashing.
Attend car shows on private property. Many car meets happen in private lots where underglow is part of the fun. That’s your best legal outlet in Washington.
Personally, I think this approach makes sense. You get the look without the risk.
What to Do If You Get Ticketed
Most people don’t realize they can sometimes fight equipment tickets. In many states, officers issue what’s called a “fix-it” ticket. You fix the problem before your court date, show proof, and the ticket gets dismissed.
Washington doesn’t have a formal fix-it ticket system for all violations. But you can still appear in court and explain yourself. If you removed the lights and have documentation, a judge may reduce or dismiss the fine.
When in doubt, talk to a lawyer. A quick consultation can tell you exactly where you stand.
Frequently Asked Questions
Is underglow legal in Washington state?
No. Underglow is illegal on public roads in Washington. You can only use it when parked on private property.
What is the fine for illegal underglow in Washington?
The fine is $124 for violating vehicle lighting regulations under Washington state law.
Can I have underglow if I turn it off while driving?
Yes. Having the lights installed is not illegal. The violation happens when you use them on public roads. Use a switch and turn them off before leaving private property.
What colors are completely banned in Washington?
Red and blue lights are banned for regular vehicles everywhere. Flashing white lights are also prohibited. These colors are reserved for emergency and law enforcement vehicles.
Are LED underglow lights treated differently than neon?
No. Washington law covers all aftermarket lighting devices, not just neon. LED and neon underglow are treated the same way under the law.
Can I use underglow at a car show?
Yes, if the car show is held on private property. That’s the one situation where underglow is allowed in Washington.
Final Thoughts
Washington makes it pretty clear. Underglow on public roads is a no-go. The law has been around for years and the 2026 update keeps those restrictions firmly in place.
If you love the underglow look, enjoy it at home or at private car events. Install a switch. Know your colors. And never drive on a public road with those lights glowing.
Now you know the rules. Stay informed, stay smart, and if something isn’t clear, check with a local attorney or your nearest Washington State Patrol office.
References
- WAC 204-21-230: Lighting Equipment Prohibited (Washington State Legislature)
- RCW 46.37.210: Additional Lighting Equipment (Washington State Legislature)
- Washington Neon Underglow Laws (NeonLaws.com)
- Is Underglow Illegal? Neon Lighting Laws By State 2026 (ConsumerShield)
- Underglow Legal States 2026 (World Population Review)
