So Amber lights (yellow) are great for bad weather conditions. Ran, snow, fog, dust, etc... They cut through the weather better then white lights will. White lights tend to bounce around on the various particles and reflect back to the driver. Whereas amber/yellow don't reflect as easily and therefore will cut through better.
If you've ever driven when it's snowing outside you know what I talk about. It's like you're in a star wars moving going through light speed, with white lights on. Amber (yellow) lights will improve this.
It's why you see european race cars using them, especially when it's raining out.
And it's also why almost every vehicle driving at night off-road has amber lights somewhere on their vehicle.
