in here you will find a few possibly useful things for emacs...
Replacement icons for Emacs
Circles
Rounded boxes
Playing cards
And if you want to build your own with the core motif, some PNGs...
Info...
Click a thumbnail to download an icon in OS X .icns format
You can find large (512px square) png's at the Emacs icons project here.
To generate icons for most platforms you can use the free online tool at: http://iconverticons.com/
Emacs Color Theme Editor
An Emacs theme editor, with the ability to edit an existing color-theme.
This is based on original work by Alex Pogosyan which is no longer online.
A Few Sample Themes...
Click a theme's caption to download it (*emacs-lisp file)