I think that you had better ask a better question... something like "I would like to have a metalic effect for snake skin". when I first read your question is seemed to me that it was taken from the perspective of a 3-D app and not within a 2D world. the best answer is to approach the issue like it truely is you have to use traditional techniques to get such effects all chrome and metalic effects are based upon reflectivity and the assumption of a enviroment within the 2D medium. either way its not anything like a 3 D approach. you'll have to create it from scatch. Welcome to the world of art.