Monitor has gone "negative"

[BigBurd]

When I booted up my 1 gHZ 17" iMac this morning, my screen had gone to "negative". No more Aqua! It now looks like a photo negative, with no color.

I've run DiskWarrior, and I've run Norton Anti-Virus to see if I could find the problem. I've also tried to find a way to reverse this in my System Preferences. Still no luck.

I'll bet this is something that I should know about, and the it is very simple to repair. Will someone help me?

Thanks!

[SilentPanda]

Try pressing Ctrl-Apple-Option-8.

[thecow]

See if anything has been changed in the universal access preferences. It should look like this:

[BigBurd]

Ctrl-Apple-Option-8 worked immediately! Thanks for your replies!

MacRumors is the best! :)