How do you retrofit projectors? Or even buy them?
You bake the headlight housing, remove the lens, cut the housing to fit a projector housing, and you're good to go. Still, retro fitting, using HIDs, modifying the headlight is still illegal. On bikes like cruisers, you would need to buy a different headlight housing, or lens because stock OEM lens have those lens that diffuses the light to spread evenly.
Most people don't care if they get blind by the HID light glare, the reason is it's only one headlight. Now try doing that to a car and you'll get yourself in trouble..
I didn't retro fit mine, I didn't change the housing, my headlight causes a bit of glare. Riders don't have any problem what so ever. What I also love is the little glare that helps you see much better at night with the signs, especially when you're trying to find a street without GPS, it's very helpful than slowing down and obstructing flowing traffic behind you.
The problem is when you ride in blocking positions, where you are supposed to be in the right lane (obviously..
) you're in the left tire track. Cagers are lower and so are their mirrors. Which means that you're going to blind them straight in the face in their left mirror.
As for colours, there are so much. Blue, purple, green, yellow, I've seen them all on bikes and cagers.