This tutorial describes one of my favorite techniques for ‘spicing’ up a photograph. This method is adapted from the color darkroom of old. In those days, innovative photographers often processed film in a chemical solution intended for another type of film. For instance, they might process color slide film in C-41 chemicals. The result yielded a most unusual shift in color, which created a very retro look. To recreate this technique using the computer is both easy and fun.