[Perfectlap]

blue and grey pads tend to be non-abrasive buffing pads for top waxes like Carnauba or finishing sprays.

White pads tend to be polishing pads for cleaning the paint using a polish like Klasse All in One, WErkstatt Prime or the Zaino polish(forget the number).

Yellow/maroon pads tend to be cutting pads for deeper cleaning or swirl removal.

I've never been brave enough to use a wool pad.

But each maker has its own color choices so its varies.

How long to use them depends but if the edges start to lose their roundness its time to ditch them. I scrape them off with a soft toothbrush and dunk them in microfiber detergent so they never get dry before washing.

p.s.
Always spray the surface for lubrication before touching it with the buffer. Same goes for manual detailing.