Glass Technologys glass polishing discs use a 5 step process depending on the depth of the scratched glass. The discs are color coated based on aggression. These progressions are from most aggressive to polish starting with GREEN PINK BLUE ORANGE AND WHITE. In order to achieve effective results users must progress down through the aggressions uniformly from whatever aggression or color is initially used. Example: If damage is removed with the blue aggression a user must then progress to orange followed by white in order to achieve a final result. White Disc (Polishing) used for polishing very light surface scratches and hard water staining on glass surfaces available in 5 inch materials. GT white polishing discs are easier to operate on the glass surface then 3M Trizact SRPD-5. These discs offer a slower release of polish onto the surface of the glass for longer use and run time.