India, Dec. 25 -- If you drive in fog quite regularly, the choice between yellow and white fog lights is not cosmetic. It has a direct impact on visibility and driver fatigue, especially in regions such as Delhi-NCR, where winter fog often reduces visibility to a few metres and contributes to frequent multi-vehicle accidents.

Fog lights are mounted low and aimed downward to illuminate the road surface close to the vehicle. Their purpose is not to throw light far ahead, but to help the driver see lane markings, road edges and obstacles without excessive glare reflecting back from fog, rain or dust.

Yellow fog lights use light with a longer wavelength compared to white or bluish light. In real-world terms, this means the light scatters le...