Idee Inc has created a really cool site aimed at letting users navigate Flickr images through color. By using the palette on the right of the MSL page you can select up to ten colors and gleefully revel in your new palette heavy image results.

and a second

This is a great new way to search for images that you need to fit a really specific color scheme. Check out the site here: Multicolr Search Lab.

Also of note is Getty's new Moodstream, which allows users to search images based on emotional parameters (happy/sad/calm/lively).

Another super cool image search tool is Tag Galaxy. This site explores search tags and their relation to similar tags, ultimately leading you to a 3D galaxy and planets of images related to your initial search request. From there you can click on an individual pic and see where it came from on Flickr.

You can see my 1st search is for one of my favorite things ever...

And Tag Galaxy responds with a giant Monkey planet in addition to animal/nature/primate/zoo/wildlife related planets. Here's what the monkey planet looks like.

Links: Multicolr Search Lab Moodstream Tag Galaxy