Make a mix of 3 parts Athonian Camoshade , 1 part Drakenhof Nightshade and 1 part Biel-Tan Green . Use this mix to glaze over the skin, pulling pigment towards the recesses.
Add a small amount of Incubi Darkness to the above mix and shade only the deepest recesses.
Highlight with Elysian Green and Ogryn Camo , mixed 1:1.
Add finer highlights, covering even less area with pure Ogryn Camo .
With a 1:3 mix of Ogryn Camo and Screaming Skull , selectively highlight the skin.
Add very small/specular highlights with Screaming Skull .
Glaze Kislev Flesh over knuckles, ears, elbows and lips. The re-add specular highlights of Screaming Skull , if needed.
Mushroom Flesh
Basecoat with Screaming Skull . I applied mine with an airbrush, so there was a nice transition.
Add soft shading to all of the flesh with a 1:1 mix of Screaming Skull and Baneblade Brown . I like to thin with Lahmian Medium .
Shade more selectively with pure Baneblade Brown .
In particularly deep recesses, run some Dryad Bark in, for extra definition. This is also a good colour for darkening the eye sockets.
As an optional bonus stage, consider a glaze of Seraphim Sepia , especially where the two flesh types blend. I found this adds a little more warmth and variation to the skin, making it look more alive.