Improving Dust Walkers
I basically used several weathering techniques on the walkers to improve the look.
I didn't change the base color as I like the basic coat the models comes with.
I made it darker with Devlan Mud,
highlighted with a green-yellow drybrush,
and I adde dark grey damages with a detail brush.
All the engine parts, machine guns, the muzzle, pistons and cables were darkened with two passages of Black Wash.
To complete I added some mud on the lower parts of the legs (Bestial Brown drybsrush + OgrynFlesh wash).