Accidental inverted colors on the desktop environment

[vmarcenne]

Hi guys,
A bit earlier, I accidentally inverted the colors from X's output in a way that everything (except the background image): the contents of this page, the video output of a movie - was inverted. Here's a screencap: http://i41.tinypic.com/fvd8ya.png

I was able to correct this with a simple reboot.

Does anybody know the key combination that does this?

Thanks guys :)

[witoff]

Winkey+M or Winkey+N invert all, and window only colors respectively.

[hictio]

You have activated by mistake a Compiz (http://en.wikipedia.org/wiki/Compiz) plugin aimed at accessibility, specifically, the Negative Plugin (http://wiki.compiz-fusion.org/Plugins/Neg).