Does anyone here use FCE Ultra ? If so, maybe you can help me with a problem. I got it to go full screen, but when it goes full screen, the colours invert like a negative. Nothing I tried seemed to get it to display the proper colours. Can anyone help ?

No. I use good emulators like Nestopia and Nintendulator.

They're endorsed by the bsnes guy:

http://arstechnica.com/gaming/2011/0...snes-emulator/