Maybe an alpine look? Rocky outcrop topped by a bit of snow/ice? Maybe a non canon arctic camo paint job? :)
It's not question of style of paint, it's mater of having no experience painting nature bases beyond painting sand green and calling it grass. :P
As for the mech's config, if I base coat it white, it'll be Hera, Gray will be Hades, Aphrodite, or Hephaestus , and black would be Zeus. Currently I've got all 6 torso's built.