Technical body paint with a brush: It is ideal to use the brush on the realization of body painting you want done with speed. With the brush is easier to do the edges and fill the different spaces. MagicColor is from Ben Nye, a Hollywood makeup company. These are opaque, but apply thin with a brush, and dry quick. (The main ingredient is alcohol.) They work well with airbrush. 4 ozs. can do whole body coverage. Price is around US$10 for a 4 oz bottle. Most primary colors are available, along with glitter metallic. Warnings are on the label against using red, pink or orange in eye areas. These are good all around makeup grade paints, not cost prohibitive, and with fairly good staying power. The red stains a little on skin, but cleans off easy. It does stay tacky for awhile, so you may want to apply setting powder.
Mehron's line of Liquid Makeup is a little cheaper, and available in larger pint sizes for about US$13. So far I've only used the yellow, which seems to go on thin, and the red. It doesn't seem as flexible as the MagicColor. But I need to try more colors