Idee is introduced the TinEye which will allow you to search images with an image, and it will display the similar images on the web. You can use this for checking your personal images or copy righted images.

try it here

Now they have another service,named Multicolr Search Lab,  which will allow to search images by color, You can choose up to 10 colors and this service will return the results from the 10 million of the most “interesting” Creative Commons images on Flickr.

Multicolr Search Lab