I have a small gallery of artwork that I've produced over the years. A friend of mine asked me a couple of years ago whether it was possible to find images in the gallery by their color; that way, potential buyers could select images that go with their existing décor.
This turned out to be a bit harder than it first appears, since the “color” of an image isn’t well-defined. But after some experimentation and a lot of testing, I was able to produce an acceptably working version.
