I'm also doing an unnatural skintone cosplay, and what I'm using, for my face, is the Ben Nye magicake makeup (which is powder), over a base of that cheap white cream makeup (it makes the colour a little less suggestive of natural skin colour.) I used two layers of the powder, each with a layer of the white in between. Since the makeup is powder albeit it comes out a little bit sticky, I use the Ben Nye Final Seal spray to keep it from rubbing.
As for my arms, I tried PAX, and it's a NIGHTMARE. My solution is just glue + water + paint (about 3 parts glue to 1 1/2 parts water) and however much paint you need to make it pigmented enough. Apply it like regular body paint, dry in between layers (with a blow dryer), and once you're happy with the opaqueness, you're good; it doesn't require powder.
*Kefka Palazzo - Final Fantasy VI (Being repaired.)
*Kankuro - Naruto
*Ryoga Hibiki - Ranma 1/2
*Soul Eater Evans - Soul Eater
*Antonio Salieri - Mozart L'Opera Rock
*Rapunzel - Tangled
*Miss Martian - Young Justice - 70%
*Monkey D. Luffy - One Piece - 60%
*Kotetsu T. Kaburagi - Tiger & Bunny - 40%
*Ryuk - Death Note - 30%
*Toph Bei Fong - Avatar: The Last Airbender - 5%