This is my take on the Lost Sons warband colour scheme, inspired by the work of Bakerb24 on the 40k homebrew site.

The main colours are blue, red, and gold.

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

Gold (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. Gently drybush over the model with Retributor Armour to even out the colour.
2. Shade the recesses and around rivets with Agrax Earthshade
3. Highlight the edges with Stormhost Silver

Blue (Armour Panels):

1. Base with Sotek Green
2. Shade the recesses with Drakenhof Nightshade
3. Highlight the edges with Temple Guard Blue
4. Add a fine highlight and scratches with Baharroth Blue

Red (Armour Panels):

1. Base with Mephiston Red
2. Shade the recesses with Agrax Earthshade
3. Highlight the edges with Wild Rider Red
4. Add a fine highlight and scratches with Fire Dragon Bright

Beige (Details - Cloth, Wraps):

1. Base with Rakarth Flesh
2. Shade the recesses with Agrax Earthshade
3. Highlight the edges and add frayed lines with Pallid Wych Flesh

Purple (Details - Lenses, Energy Cables):

1. Base with Naggaroth Night
2. Shade over with Nuln Oil
3. Layer the middle with Xereus Purple
4. Add highlights in a pulsing pattern with Genestealer Purple

Black (Details - Armour Ribbing, Gun Casings):

1. Base with Abaddon Black
2. Highlight the edges with Eshin Grey
3. Add a fine points and scratches with Administratum Grey

Brown (Details - Leather Pouches):

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