Start with some GZG mercs, and a few paints. I used Green, Antique white, sable brown, Black, red, yellow, white, silver (metallic), Polyshades dip, Testers dull coat.
With the two colours below I mixed up most of the uniform, gun, armour, and boots.
Bellow are the Orcs ready for dip, and I have brushed it on.
Once the dip is dry, I sprayed with dull coat, and hit some detail work.