12. Finally, make sure you pre-bake them for about 8-10 minutes on 200 degrease or heat them with a heat gun. Most high temp paints will change color and release chemicals. This will make your headlamps foggy inside or make a rainbow like film inside if not preheated. This is another reason to use a flat color. It will typically turn into a semi-gloss once it’s exposed to heat. Now you're ready to seal them back up.