All 8-bit sprite tiles have only three colors plus transparency as a fourth color, but Bowser's original sprite from Super Mario Bros. appears to have four colors as well as transparency as a color. This is because the black background is what gives Bowser his black spiked collars around his wrists. Due to this, using cheat codes so Bowser appears in a non-castle level will look like his hands are separated from his arms. This occurs again in Super Mario Bros. 3 where Bowser's sprite is designed to exploit the black background and use it as an outline element.