The Army Painter now has the paints from their Zombicide Warpaints sets available as singles to order from their webshop.
From the announcement:
While the two Zombicide Paint Sets already are in stores all over the world, the individual Zombicide Warpaints are available for pre-order from The Army Painter webshop.
This gives you a total of 13 brand new Warpaints.
REMEMBER: you still save money when you buy the whole set instead of the individuals.
Release date for the individual paints: 8th September.