idee Multicolor Search Lab
http://labs.ideeinc.com/

They extracted the colours from 10 million of the most “interesting” Creative Commons images on Flickr. Using their Piximilar visual search technology you can search the collection by colour. Idée Labs is Idée’s technology playground for visual search and image recognition. Here you will be able to experiment and play with various implementations of Idée’s visual search technologies. The Visual Search Lab allows you to browse through nearly 3 million stock photos from Alamy using Idée’s Piximilar technologies to find images that look visually similar. Combine keywords with your visual search to make your results even better. Click on an image to retrieve visually similar images. Or enter a keyword first, and then select an image. This has been added to the tools section of Research Resources Subject Tracer™ Information Blog.