Color we used factory gunmetal color and tinted it darker..that's best I can tell you.as far as class not sure.i built it for street and strip..I have never ran in a Buick class before..always just went to track and have fun with my buicks.i guess tso would be closest it could run in due to stage 2 block and stage 2 heads,only a 76 billet turbo on it ,for easy street boosting.