Legality & illegality of Strobe Lights in the US
The car strobes lights are not illegal, however, there are certain restrictions of some kinds of vehicles are allowed to use strobe lights in the US, which vary state by state. Generally speaking, car strobe lights are permitted to used on personal vehicles when in parks, in downtown roads and on private property.
In general, car strobe lights are not permitted in public streets, but on private property. If you buy vehicle strobe lights for car shows which will immediately be in the spotlight, and there’s no need for you to worry about breaking the law.
On agriculture, farmers also get the strobe lights installed to help them patrol their fields and examine the crowd yield even in the dark time.
Strobe lights are also applied for surveillance on privater property of some security vehicles, which are mostly seen from parking lots to amusement parks.
On police cars, fire trucks and ambulances, strobe lights are red and blue with sirens so that they can alert other drivers their presence as soon as possible. So in general, red and blue strobe lights are only legal for fire trucks, ambulances and police cars on public roads, which are associated with emergency cases alerting the pedestrians and other drivers to set aside as needed. Therefore, in most cases, there is a heavy fine for attempting to impersonate a police officer with the red and blue strobe lights flashed.