A grey rotten wood.

Wood

1. Skavenblight Dinge Basecoat
2. Agrax Earthshade Wash
3. Stormvermin Fur Painted wood grain
4. Dawnstone Further define wood grain
5. Karak Stone Select highlight of the wood
6. Rakarth Flesh Spot highlight

Moss/Mold

1. Castellan Green Sparsely stippled on select areas
2. Elysian Green Stipple highlight the centre of the moss
3. Athonian Camoshade Lahmian Medium 1:2 glaze if it is required to tone down the moss