Is the color showing on RAW files, or the camera monitor, or both? If the files, try a firmware update and see if that fixes things. Also try doing a reset to factory defaults. If these don't work could be a sensor(rare) or main board failure. Impossible to tell just what the problem is without a tear down.
If just the monitor, could be a flex connection problem or failing main board. Even when saving to RAW, the image on the monitor is a jpeg.