Ok first off, forgive me, i am a cop so i have to throw my two cents in, red and blue are illegal on any citizen owned vehicle period. Even volunteer firefighters cant have em. They use green lights. And second yes yellow and white are legal to have on your car. And yes this guy may have been a city worker, but it is illegal to use those lights to pass some one, run a red light etc when you are not acting in your "official capacity."
Forgive you for what it's been said like 5 times already.