Undercoat Imperial Fists from sprue to their base of yellow.

Imperial Fist Yellow Armour

1. Undercoat Wraithbone & Lahmian Medium 1:1
2. Sponge on Screamer Pink focus on where dark areas will be, light source above model looking down (from table top angle)
3. Sponge on 50:50 blend of Screamer Pink & Wraithbone to blend joins of steps 1&2.
4. Base armour with Imperial Fist