Can you cite any actual federal law on this? I know all states have
> laws on it but it varies from state to state, for example, a volunteer
> FD member can't legally drive their NY vehicle with a blue light (even
> if not turned on) in Arizona because AZ prohibits "any blue light or
> lens that's visible....except on authorized emergency vehicles". AZ
> won't even put blue on their own DOT Snowplows because of the
> restriction. Other states do put blue on their snowplows. I've seen
> reports complaining of a lack of uniformity between states and I've
> never seen anyone cite a federal law that covers OPERATING with
> lights, which is different then simply manufacturing something which
> may or may not ever wind up on the streets.
I don't believe there are any federal laws on such things. There are of course regulations on the performance and color of brake lamos, turn signals, marker lights, headlamps, etc. I don't see anything in the USDOT regs. Doesn't mean it isn't there but it doesn't appear on a quick look. I think it's all left to the states.
Also keep in mind that states have different laws regarding regular lamps as well. Sometimes the state minimums are pretty crappy which makes a lot of idiotcy of aftermarket and customized lamps technically legal.