Makes use of Sonic Sledgehammer's Marine Juice MKII:
https://youtu.be/pHtEcYh9CAE?feature=shared&t=285
and Midwinter Mini's DIY dip wash:
https://www.youtube.com/watch?v=mUX9T_qEIYo

Prime/Undercoating

1. Any black Primer covering the whole model
2. Light-ish airbrush zenithal of Intermediate Blue
3. Overbrush/drybrush of Intermediate Blue

Pants and backpack case/breathing pack

1. Gravestone Blue

Gloves, tubing, devices, future metallics

1. German Grey

Mask and putties

1. Spaceship Exterior though could be more tan

Finalize coat

1. Drybrush with Longbeard Grey (Optionally Gravestone Blue to reinforce blue)

Leather boots, harness, pouches

1. Chocolate Brown
2. Edge highlight and weather with Parasite Brown

Metal armor, helmets, goggles

1. Black Metallic
2. Highlight edges and prominent bits with Chrome
3. Fill in goggles, belt buckle, and Dot rivets with Chrome

Gun

1. Metal Gunmetal Metallic
2. Wood Leather Brown

Finalize

1. Wash everything with Sonic Sledgehammer's Marine Juice MkII mix (1 part each Reikland Fleshshade , Dark Tone , Lahmian Medium )
   
   
   Alternatively: Agrax Earthshade
2. Varnish Anti-Shine Matt Varnish (Optional)

Base

1. Prime base then coat with brown or black ink (if not already black)
2. Slop on Stirland Mud
3. Wash with home-made burnt umber ink dip wash ala Midwinter Minis: https://www.youtube.com/watch?v=mUX9T_qEIYo
4. Drybrush with Sylvaneth Bark
5. Dab brown pigment powder onto model legs, alternatively dab/stipple/drybrush Stirland Mud sparingly on lower bits