Keeping only one color in your image
Altering the color space of an image isn't always about correction. Sometimes we want to achieve some artistic end, whether it's to make a statement or simply draw viewers' attentions in a particular direction or manner. One simple way to do this is by the absence of color. Color in video is so commonplace these days, that desaturated (black and white) images tend to be far more dramatic or eye-catching despite not properly representing reality. Desaturating an image with the exception of single color—well, that's just crazy! Actually, it's not at all. Just take a look at modern classics like Schindler's List, Pleasantville, or even commercials for Gatorade to see effective uses of this technique.
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If you haven't read the previous three recipes, it'd be a good idea to go check them out now!
Find a colorful clip in your repertoire to see this effect dramatically. Removing one color works best if that color is fairly consistent in the clip with...