Laser color marking is a technique whereby the surface of a metal is colored by laser irradiation. Although a great deal of literature is available on colorization in pursuit of such processing conditions as laser control parameters and process parameters, it is difficult to colorize for a desired color by exhaustively searching the processing conditions. In this review paper, we describe the basic principle of thinfilm interference present a different approach from conventional research, and touch upon examples of applications on knives and future prospects.