These Space Opera Robots are from Hydra Miniatures Retro Rayguns range, available in the UK from Wargames Emporium.
They were sprayed with white undercoat, then silver and finally brass. Oil leaks around the joints are Citadel dark brown wash..
The bases are Tamiya grey textured paint, Citadel snow, and little chips of chalk stone to look like the China Clay pits at St Austel, or the Moon as you prefer.
The blue ray gun projectors are Cote d'Armes metallic blue (ex-Citadel).