Let me give you a piece of advice. Never mess with a man's computer. Unless it's a harmless prank like this one for inverting the colors on any Mac OS X machine. Use this keystroke combination:
Go ahead and try it. Use the same keystroke to go back to normal. Like every other prank, the set up is most important. So before you start control-opt-command-eighting all of your friends, you might want to tell them about the new Mac virus that's corrupting LCD displays. Have fun!