Recess shade with a 1:1 mixture of Imperial Blue , Abaddon Black or Black let down to a wash consistency with either water or Lahmian Medium , enough to flow into gaps.
At this point paint the armour carapace.
Glaze highlight with a 1:1 mix of Macragge Blue and Ultramarine Blue .
glaze again volumetric with Ultramarine Blue x 2, refining on the second pass.
Tidy up any shading with Nuln Oil .
Edge highlight with a 1:1 mix of Macragge Blue and Ultramarine Blue .
Pick up only raised edges with another pass of Ultramarine Blue
Refine further with Fenrisian Grey .
Dot highlight with Blue Horror .
Carapace
Basecoat with your chose Black.
Highlight with Eshin Grey .
Slightly drybrush with Leadbelcher .
Gold Trim
Basecoat with Balthasar Gold .
Wash with Reikland Fleshshade .
Highlight with Gold .
Recess shade with Skeleton Horde .
Final highlight with a 1:1 Stormhost Silver and Gold .
White Details
Basecoat with Administratum Grey .
Drybrush over with Corax White .
Recess shade with a mix of Corax White and Lahmian Medium .
Drybrush again and edge highlight with White Scar .
Red Details
Basecoat Khorne Red .
Highlight with Mephiston Red .
Recess shade with Agrax Earthshade .
Further highlight with a 1:1 of Mephiston Red and Wild Rider Red .