Ok so i decided to play some starcraft today as I await playing the new game, when I put in my Brood War expansion disc, all the colours were crazy bright rainbow-ified, but when I play with the original disc it's fine. I know the disc isn't broken because it worked fine the last time I used it, and I take good care of my discs.

 

Any ideas on how to fix it?

Yes, It happens to me all the time. You have to change your system preferences to display 16bit colours, rather than 32. I then usually run it in compatibility mode with Windows 2000 (or is it 95? Check on the disc) and select colour compatibility for 256 colours. If that still does not work, I press the alt and tab keys a few times.

Worked, thanks a lot. :D