from CMA's site...
White Polishing Pad - The most often used pad. This pad has a mild cutting (cleaning) action and should be used to apply polish and/or wax to newer vehicles with or without a clear coat finish.
Use this pad for polishing with
Meguiar's No. 3 Machine Glaze,
No. 9 Swirl Remover, Medallion Premium Paint Cleaner and applying one-step cleaner/wax/protectant products like
Meguiar's No. 6 Cleaner Wax, Medallion Premium Paint Protection and
Klasse All-In-One.
Use white pads to apply one-step products like
Klasse All-In-One.
You should not use the same pad to apply both polish and wax. If you are performing both steps you should use one pad for polishing and another pad for waxing.
Grey Finishing Pad - This pad has no cutting or cleaning action. It should be used to apply the finish coat of wax or to layer one product on top of another.
Use the White Pad to apply Klasse All-In-One and then follow with Klasse High Gloss
Sealant Glaze using the Grey pad.
Always use the Grey Pad when building up multiple layers of wax or surface protectants.