Okay so I'm absolutely positive I'm retarded now. I have to do a few of these because I don't want this client using Java rollovers on their store, I want to do it properly in CSS. So instead of two images, I need just one image twice as wide so I can refer to it by offset and voila. Here's a sample of two of the images:
http://www.serpentstudios.com/test/twitter.psd
http://www.serpentstudios.com/test/twitter-gray.psd