Here is the secret. Mixed into the clearcoat is a small amount of black paint. Mario made several light passes with the spray gun. With each succeeding pass, the lenses gradually got darker, giving them a "smoked" look. The key is to make several light passes. If you get them too dark, you will have a miserable time sanding all the clear off and starting again. After he smoked the lenses, he then sprayed them with a regular clearcoat to give them some shine and protect the color.