|Does 'off' mean it gives a monochrome display or just that the colors are different than what they should be?|
First determine if it's a hardware or windows problem. Does the problem show on the posting or logo screen or just when windows opens? Are there any color adjustments in bios setup such as color temperatures?
Try an external monitor and see if the color is 'off' in the same way. If so it may be a windows setting for your graphics adapter.