the best way to tint lights is to get some legit black automotive paint (not duplicolor from autozone either)and reduce it out then clear it, it works awsome and you can use it on all lights and lenses. that is how my tail lights on my mustang are done and they are so glossy it will make your truck look scratched. I am going to be doing this for a small fee very shortly for any body that would want to send me there lights.