Now I discover it gets even better with a new tool called Idée that allows you to search according to color across the entire Creative Commons Flickr territory. Whether you comb the site for inspiration or to find images for blogs and projects, this is an efficient and fun way to narrow your search.
The Multicolr Search Lab for Flickr is just one of several offerings from Idée Inc, a company that has developed technology to find and extract visually similar images from giant digital collections. In addition to the Flickr engine they have searches for stock photography sites and tools to allow you to pair visual cues with tags or upload and compare an image of your own to those in the public domain. This is a site worth playing around with and bookmarking, just beware: it's addictive.