Scorched Brown - armour.
Codex Grey - hands, feet, claws.
Bleached Bone - claws, teeth.
Desert Yellow - wires.
Tallarn Flesh, Dwarf Flesh, Ogryn Flesh, Baal Red - severed head.
Badab Black, Delvan Mud, Brown Ink - Metal.
Red Gore - tongue.
Watered down Leviathan Purple was used on those slits on his legs and arms (I'm not too keen on doing that again). It was also applied to the armour on his back, watered down Badab Black was also used in places on his back and also for shading various recess areas such as between the fingers etc.