Here is how I painted the big daddy Genestealer for my Broodcoven. This is the traditional Genestealer scheme and could easily be used on the standard Tyranids, Genestealer Cults or Acolyte models.

Genestealer Shell

1. Basecoat with 1:1 Kantor Blue and Abaddon Black .
2. In the very deepest recesses, shade with some thinned Abaddon Black .
3. Glaze the majority of the shell with Kantor Blue , pulling your brush towards where highlights should be.
4. Add edge highlights to everything with Sotek Green . In tight areas, keep them pretty fine, but make them nice and chunky around corners, curved edges and placed that would catch more light.
5. Edge highlight all of the areas that got chunky highlights with fine edge highlight using Temple Guard Blue .
6. Selectively highlight corners, curves and points with 1:1 Temple Guard Blue and Screaming Skull .
7. Finish with very small specular highlights of Screaming Skull , where you want the shell to glint.

Genestealer Skin

1. Basecoat: Warpfiend Grey & Genestealer Purple 3:1
   Shade: Druchi Violet
   Highlight: Warpfiend Grey
   Highlight: Slaanesh Grey
   Highlight: Slaanesh Grey & White 1:1
2. Basecoat with 3:1 Warpfiend Grey and Genestealer Purple .

Where the neck meet the shell on the chest, I glazed it down by adding some Xereus Purple , then more selectively with pure Xereus Purple . I did this before the wash stage to keep everything unified.

Heat Vents

I followed the same method for the 'Genestealer Skin' on this element, with one difference. When it came to the shading, I washed it with 2:1 Druchii Violet and Volupus Pink , then highlighted as normal.

Patriarch Brain

1. Basecoat: Genestealer Purple
   Highlight: Add Ungor Flesh to Basecoat
   Highlight: Add Ushabti Bone to previous mix
   Glaze: Thin glazes of Screamer Pink, Evil Sunz Scarlet, Liche Purple, Naggaroth Night