I know this is a long shot, but I was wondering if Python had a way to manipulate the screen buffer. Specifically, I want to be able to gray-out my desktop and highlight my windows when I press a key combination. Is this in the realm of possibility?
Instead of "graying out" the desktop, try to overlay a gray, semi-transparent image over the entire screen and then make sure your window is on top of that. You may face a couple of minor limitations; for example, I don't know off the top of my head if it's possible to overlay the mac menubar (and I'm not sure you'd want to).
Manipulate screen buffer in python