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 with 3:1 Warpfiend Grey and Genestealer Purple .
2. Shade recesses using Druchii Violet . Rather than doing an all over wash, use a thin brush and run it into recesses, or shade via glazing.
3. Apply general highlights with Warpfiend Grey . This is very similar to the basecoat, so be quite generous.
4. Apply fine highlights with Slaanesh Grey .
5. Mix your Slaanesh Grey 1:1 with White .
6. Finish with specular White highlights, where appropriate.

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.

Black Claws

1. Basecoat with Black .
2. Apply chunky highlights of Skavenblight Dinge ..
3. Add a little Ivory (or an off-white of your choice) to the Skavenblight Dinge , and apply fine edge highlights.
4. Increase the amount of Ivory in the mix and selectively highlight. You might need to do this in a couple of progressive stages, depending upon the size of the claw.
5. Finish with specular highlights of pure Ivory on the tip.

Patriarch Brain

1. Basecoat with Genestealer Purple
2. Glaze with Screamer Pink , pulling your brush away from the centre, always.
3. Overbrush with 1:1 Genestealer Purple and Ungor Flesh , picking out the raised details.
4. Add fine highlights to the raised details with Ushabti Bone , going a little heavier towards the centre.
5. Selectively highlight with Ice Yellow , making them more concentrated towards the centre.
6. Finish with a few specular highlights of White , I bet you can guess where you should do more.

Pink Tongue

1. Basecoat with Screamer Pink .
2. Shade with Druchii Violet .
3. Pick out the raised details with 1:1 Screamer Pink and Pink Horror .
4. Add chunky highlights with Pink Horror .
5. Do fine edge highlights with 1:1 Pink Horror and Kislev Flesh .
6. Selectively highlight with Kislev Flesh .
7. Add some Pallid Wych Flesh to your Kislev Flesh and add a couple of specular highlights.

Yellow Eyes

1. Pick out the eyes with Yriel Yellow .
2. Selectively highlight with Ice Yellow towards the middle.
3. Finish with a small highlight of White in the middle.

Teeth

1. Basecoat with XV-88 .
2. Highlight with Ushabti Bone .
3. Selectively highlight with Screaming Skull , towards the tip.
4. Finish with a dot of Screaming Skull , mixed with some White .