This is my take on the Warhounds scheme. After the discovery of the Primarch Angron, the Warhounds would be reborn as the World Eaters.

The main colours are a pale blue, cool white, and brass.

General Information:

My general method is to lay down all the base colours for the model, then do all the shading in the recesses before moving on to the highlights.

I don't own an airbrush, so the recipe will mainly consist of brush on paints.

Priming:

I find the metallic sprays from GW tend to be a little on the transparent side, so an initial undercoat of grey helps.

1. Prime the model lightly with Mechanicus Standard Grey
2. Prime over that with Retributor Armour

Brass (Armour Trim):

I generally start with the armour trim so that any time I get paint on another piece its easy to cover later.

1. Drybrush over the model with Balthasar Gold
2. Shade the recesses and around any rivets with Agrax Earthshade
3. Highlight fine points and sharp edges with Stormhost Silver

Pale Blue (Armour Panels):

1. Base with Thunderhawk Blue
2. Shade the recesses with Nuln Oil
3. Highlight the edges with Fenrisian Grey

Cool White (Armour Panels - Shoulder Pads, Backpack):

1. Base with Celestra Grey
2. Shade the recesses with Agrax Earthshade
3. Highlight the edges with Ulthuan Grey
4. Highlight fine points with White Scar

Red (Details - Lenses, Cloth, Wraps):

1. Base with Mephiston Red
2. Shade the recesses with Agrax Earthshade
3. Highlight the edges with Evil Sunz Scarlet
4. Add a fine highlight of Wild Rider Red
5. Highlight fine points with Fire Dragon Bright

Grey (Details - Armour Ribbing):

1. Base with Mechanicus Standard Grey
2. Shade the recesses with Nuln Oil
3. Highlight the edges with Dawnstone

Silver (Details - Weapons, Chains):

1. For grenades, replace Nuln Oil with Athonian Camoshade
2. Base with Leadbelcher
3. Shade the recesses with Nuln Oil
4. Add a rust effect with thinned Skrag Brown
5. Highlight sharp points and fine edges with Stormhost Silver

Brown (Details - Leather Pouches):

1. Base with Rhinox Hide
2. Shade the recesses with Agrax Earthshade Gloss
3. Roughly highlight the edges with Skrag Brown
4. Add a fine highlight with Ushabti Bone