From the modeler…

Paints used (Citadel and Vallejo)

Main armor: Caliban Green-base coat, Warpstone glow-highlight, Mechanics standard grey-base coat, Dawnstone-base coat, Nuln oil-wash

Inner frame: Lead belcher-base coat, Nuln oil – wash, Necron compound- dry brush

Weapons: German grey- base coat, Mechanicuc standard grey- base coat, Dawn Stone- base coat, Lead Belcher-base, Nuln oil-wash

Weathering:

Paint chipping: Lightened tone of base coat, German grey, Lead belcher, Necron Compound- dry brush, Agrax Earth shade- wash

(Source)