You can find this in the free citadel painting app. Reproducing here so I can follow on the big screen

Undercoat

1. Chaos Black

Basecoat

1. Retributor Armour Brass areas
2. Rakarth Flesh Bone areas
3. Waaagh! Flesh Green skin
4. Abaddon Black Black areas
5. Leadbelcher Metal areas
6. Khorne Red Bracelets
7. Mephiston Red Bullet casings and helmet skull logo

Shade

1. Agrax Earthshade Brass, Bone, and Metal areas + Bullet casings & Skull logo
2. Biel-Tan Green Green areas
3. Nuln Oil Metal areas

Base

1. Steel Legion Drab All areas
2. Stirland Mud All areas