Some jurisdictions also have regulations for how many auxiliary lights you can add to a vehicle( total number of sources on at any one time) , what color they are, , what height they need to be from the road and how they are aimed. Check the laws in your area.
yea, that really varies from state to state, so as he says you need to look up local restrictions. As far as I have heard, NY, CA, and PA are the only ones that really crack down on anything besides colored lights.
Most states have prohibitions on lights that strobe or flicker (seen cars with malfunctioning lights pulled over for 'strobing') especially if they are in a color used by Emergency Services (red, blue, green). Some states also prohibit constant on lights in an EMS color.
Most states on paper require "off-road" lights to be covered when you're on the road. IN doesn't allow any lights above 42 inches off the ground, but out here, like 15% of lifted trucks have light bars above the windshield without any recourse. IN has also been supposedly cracking down on headlights that are not in the "warm to cool white" range, particularly headlights that are objectively blue, or objectively yellow, but I haven't seen a real change in people's driving habits.
The one I wish I could have seen get pulled over was the ass-hat in a jeep with color-changing halo and fog lights that was cycling through the rainbow. at least they were syncronized, lol.