Hobby work for Warhammer, Warhammer 40K, Warmachine, Hordes and the scratch built terrain that goes with the hobby.
I think a bit of a wash on the zombies would make them come up nicely.
Yeah, wash the zombies with flesh tone or brown and they should pop. With regard to the oxidization, just wash it with a green in the "creases" and that may help tone it down. Otherwise looks neat.