Headlamps with high intensity discharge, commonly referred to as HID headlights, made their original debut on some luxury vehicles but can now be found on other cars, usually due to after-market modifications by owners. HID lights emit a bright, blue-white light similar to natural daylight, which can improve both night and peripheral visibility, making it easier to see street signs and pedestrians. However, they are far from perfect; they also produce a glare that makes it difficult for other drivers to see when traveling on the same road. California prohibits the use of HID lights that are not white or yellow in color.
Headlights Must Distribute White or Yellow Light
HID headlights are not explicitly outlawed under California law. The state's vehicle code requires headlamps to distribute light that is white or yellow in color. HID headlights that emit a blue light are illegal in the state. HID lights are also legal in California, and elsewhere in the country, if they meet the safety standards of either the U.S. Department of Transportation or Federal Motor Vehicle Safety Standards, which is typically indicated on the equipment. However, some HID headlight manufacturers have falsely claimed their lights have DOT approval. Even if a vehicle's HID lights are white or yellow, they could still be illegal under federal law if they include aftermarket modifications that don't utilize the vehicle's existing light source.