How can the colors of a single window be inverted in OS X?

Solution 1:

You can use Command ⌘+Option ⌥+Control ⌃+8 to invert the video colours of the whole screen.

There's no way to just invert the colours of a single window.

Solution 2:

++ctrl+8 does the whole screen if that helps.

You could make the window full screen!

Solution 3:

In Mountain Lion, the Ctrl+Opt+Cmd+8 shortcut was deactivated. I first had to activate it for it to work via Keyboard Shortcuts in the System Preferences in the Accessibility tab.

keyboard preferences showing accessilibilty tab