This is really awesome. For anyone who wants a naive, poor man's implementation of this, I have an unfinished Ruby gem that's a good starting point for you: htt

This is really awesome. For anyone who wants a naive, poor man's implementation of this, I have an unfinished Ruby gem that's a good starting point for you: https://github.com/JoshSmith/kaleidoscope https://github.com/JoshSmith/kaleidoscope Here's how I got it to work (cribbed from my own README): TL;DR: I used k-means clustering to segment a database of images into color bins for quick searching. Using imagemagick, I ran histograms on images and converted their top n most frequent colors into Lab* color space for an approximate representation of human vision. Colors were then matched to a user-defined set of colors using Euclidean distance, i.e. a "bin". I could choose any array of RGB values of arbitrary length. I then stored hexadecimal values of the image's original color and the matched color, along with the frequency of that color within the image (for sorting based on frequency) and the Euclidean distance (for sorting by tolerance). Then finding images close to a certain color was as simple as Photo.all.with_color('#993399') and order by frequency and Euclidean distance. Here's a photo of the results: https://github-camo.global.ssl.fastly.net/89cc87ac84cd3a1d1223e8f9d560e65eb8447ef6/687474703a2f2f636c2e6c792f696d6167652f336e3243313631373069306b2f53637265656e25323053686f74253230323031332d30322d30352532306174253230362e35362e3434253230504d2e706e67 https://github-camo.global.ssl.fastly.net/89cc87ac84cd3a1d12... I might spend some time reverse-engineering Shutterstock's implementation, since it sounds way better than mine and clearly works at scale. But for my purposes, my own implementation worked just fine. If you want help implementing it, feel free to reach out to me!