Hi Erik, 
Sorry for any frustration with your not being able to reply to that thread - I closed it as it was getting unwieldy, and a lot of pictures would no longer load as my actual website has been down. 
New thread with all my twilight work is here(not that I've done any lately  

 ) : 
http://www.worldoftwilight.com/forum/index.php?topic=2044.0Anyway, in answer to your question. 
The red/ brown skin is old games workshop Fermin brown, washed with Windsor Newton peat brown in. Thenback in with pure Fermin brown before adding White for a stage or two of highlights. 
The khaki skin tones are just that. Citadel graveyard earth, then 50/50 mix with Kommando khaki, then pure kommando khaki, and I might have done a final highlight with a little white added in- I don't recall, but I have that as a premixed highlight, so it's quite probable! 
Thank you for the kind words on my work  - there's a lot of great painters on these boards to draw inspiration from!