You can make a sort of lipstick consistency makeup out of castor oil or liquid vitamin e (both have a thick kind of syrupy consistency) and just add powders to it. For more opaque colors, i'd add some white foundation base. Otherwise, the really pigmented/matte colors work best for liquid makeup:
http://host.silknaturals.com/creb/advan ... i8a6lojh42 Heavy foundation base makes a great white, coal eyeshadow base makes a great black, etc. Most of the powdered reds aren't true reds when mixed, but for a red or a pink, you might as well pull from your lippies and set with powder. Bombshell is a great red. In general, something like castor oil will air out to a powder finish, but you can also set it with powder to speed the process along.
Getting powders wet (with a hydrosol or water) will help them stick, and topping them with loose powders will up the coverage, but won't necessarily give the coverage you want for halloween makeup. For something like a whole white or green face(green color corrector), i would probably use this method just because of the amount of powder you could end up needing for halloween grade coverage.