Do you get this color issue in any other games?
Could be a corrupted drive. You might want to try completely uninstalling all AMD drivers by first running the AMD uninstaller then running Driver Fusion and CCleaner (both 3rd party applications) to remove any remnants of the AMD drivers (the AMD uninstaller is notoriously bad at completely removing all traces of the drivers).
Link to driver Fusion:
http://treexy.com/products/driver-fusion
Link to CCleaner:
http://www.piriform.com/ccleaner
Driver Fusion isn't free but the trial works fine and CCleaner is totally free and a pretty awesome utility for registry cleanup.