My desktop screen keeps fading and loses normal color.?

The screen color fades like to light blue or light greenish shade. And the normal color on screen ,icons tabs and all windows and options very thing fades. Then suddenly the orignal normal color returns n disappear in few seconds. I recently formatted my comp after that on that day every thing was ok but the next day the same problem started again....is dis any hardware issue or jus software problem as it remained okay for one full day on the day I formatted and installed XP and drivers. Thank you cheers!!!