He has also posted a painting guide on the Lead Adventure Forum:
A list of colours/washes I´ve used.
I used (on the first pic from left to right) Vallejo Model Colour for the basecoat on the shirts:
Green Ochre 914 - Green Brown 879 - Desert Yellow 977 - Khaki 988.
I can´t rememeber it, but it´s possible that I mixed some khaki into the DY. For a wider variety of shades I´ll mix this colours with each other.
Then I applied several layers of Army Painter Soft Tone (Gryphone Sepia) and Strong Tone (Devlan Mud) thinned with water. I used the Dark Tone in the folds to create depths. After everything was dry I highlighted with the base colour plus some Pale Sand 837. For the case that the highlight turns out to bright I tone it down with base colour plus a lot of water. Hope that helps,
Here's the link to Lt. Hazel's blog: http://theleutnantsdiary.blogspot.de/