Picture Search
It might help you to find pictures by color, so you can finally organize your collection of Konata's pictures, or maybe your photos, or find pronz on your friend's computer, I dunno. Add some folders to index, click ok and take a nap, come back and search all you want. You can start searching while index is building, but results will be limited to indexed files.
Technical details: Picture Search index stored in database, two database system supported: Mysql and Sqlite. Mysql requires Mysql server, and it's quite faster, Sqlite is slightly slower, but doesn't require server. Choice is yours.
Picture Search is freeware.