This video shows the whole process on how to paint a new Dark Mechanicum Serperos Overlord Heavy Stalker, that Games Workshop sent me as an early review copy. The model is painted to a good tabletop standard.
The following paints were used:
Games Workshop: Darkoath Flesh Contrast, Contrast Medium, Agrax Earthshade, Rhinox Hide
AK: Anthracite Grey, Pastel Blue, Deep Orange, Black, Deep Green, Light Green, Volcanic Yellow, Ice Yellow
Vallejo: Metal Colour Exhaust Manifold, Metal Colour Gold