Things like lenses and faces have not been painted yet. I have to wait till I dull coat the models to remove the semi-gloss protective coat on them right now. If I don't do that the acrylic paint beads up on the lacquer surface. Normally I wouldn't take a photo of models while in this state, but I like these guys. They get a pass.
So what about basing? Cracked red martian earth would be a good base color. Alternately, I could mix up some plaster and weathering powder and make mud. That would let me splash wet mud all over their feet, and have pools of yellow water effects. The counter to that is that orange/red cracked dusty bases would contrast really well with the cool green.