I believe bicycle headlights are regulated by the states, so you would have to search the regulations by state.

I have heard of red stripe laser rear lights. So far I haven't chosen to use them as my choice is to be visible, and allow cars to choose how to safely pass.

I have seen multi-colored wheel lights, and nobody seems too concerned with them.

If your green box projected 100% to the ground, and the bulb was not visible from in front of the bike, then if you ever are nabbed, you could likely argue that it isn't a headlight at all.

But, you may be required to also have a white headlight on the bicycle at night.