I know that in most States and especially in the State of Michigan that tinted Tail lights are illegal.
The law states that Tail lights must be completely red in color and very visible within 1,000 feet from the rear of the vehicle without being tinted.
The Tail lights are there for a safety reason and those Tail lights need to be clearly seen.
However the laws are different for the headlights and most states don't make it illegal to Tint your headlights as long as 50% of the light is not dimmed.
But then again it could be illegal in your State.
Since I don't know what State you're in I can't give a clear answer but as long as you don't Tint Your Tail Lights which is illegal in most if not all States then you should be okay.
But local laws can vary.