From what I understand the Kaolin white stuff is the mildest and doesn't suck out oils like the French gree will. The french green is the best for acne, blemish prone skin as it sucks more oils, great for a weekly treatment. The Rhassoul is a red and stronger and filled with all sorts of minerals and stuff. Probably the most luxurious for a weekly treatment if you don't want to treat blemish prone areas.
If the red is too strong for you mix it with some Kaolin to tone it down a bit. Or for more frequent use use Kaolin or if you have super sensitive skin.
That's my understand but I'm just new to this stuff.