Laws vary state to state.
-Red&blue is illegal everywhere.
-In many (but not all) states, just red is illegal (emergency vehicles).
-Bulbs showing is illegal in most, but not all states (indy is fine, you ought to see some of the ugly exposed s***).
-Running w/ lights is NOT illegal in all states (again, Indy is fine w/ it)
Your BMV/DMVmight have something on the website. Experienced sound/appearance installers in your area should be able to rattle off all the rules at will.
Happy hunting!
Feliz Navidad!
Veni Veni Veni (I came, I came, I came)