Most vehicles have standard headlights that emit yellowish light. However, there are bulbs on the market that are different colors. They’re marketed as “blue” or “super blue,” and there is a great deal of uncertainty around their safety and their legality.
Yes ... but no
First off, understand that “blue” headlights aren’t actually blue. They’re bright white. They only look blue because the light you’re so accustomed to seeing from a car’s headlights is actually closer to yellow, not white. This color light applies to three types of headlights currently in use:
LED headlights: These can appear blue, but are actually white.
Xenon headlights: These are also called HID lights, and they can appear blue, but really emit white light.
Super blue halogen: Blue or super blue halogen bulbs also produce white light.
This means that they are legal to use. The only color headlight that is legal to use in any state is white. This means that you cannot use any other color headlight.
Every state has its own specific laws governing the legal color of headlights, as well as when they should be used. Most states mandate that the only allowable colors for lights on the front of a vehicle are white, yellow, and amber. The rules are just as strict for tail lights, brake lights, and turn signals.
Why not other colors?
Why can’t colors other than white be used for headlights? It’s all about visibility. If you were to use blue, red, or green headlights, you’d be less visible to other drivers at night. You’d also have less visibility when driving at night, and driving in foggy conditions with colored headlights would be incredibly dangerous.
So, you can definitely install “blue” or “super blue” headlights because the wavelength of the light is actually white. However, no other colors can be used.
This article originally appeared on YourMechanic.com as Are Colored Headlights Safe and Legal? and was authored by Valerie Johnston.