My Khador scheme is very similar to the one you pictured, perhaps a touch more brown.
I used Vallejo colors for mine but I do happen to have a recipe that might work for you;
My basecoat is about a 1:1 mix of Scorched Brown and Graveyard Earth. It makes a kind of milk chocolate color. From there I keep adding a little bit of Graveyard Earth at a time. I try to go through all my browns at once just so I can keep working with the same batch and don't have to find the same spot in the "sequence" later. I'll do somewhere about 5 or 6 blends of the two colors before getting to pure Graveyard Earth. For the final highlighting/edging, I'll mix Graveyard Earth with a little bit of Kommando Khaki.
This came from a guy on the
PP forums named "OldOneEye", my color scheme is based off of his, which is based off of the original 5th boarder scheme which is what the mini you posted a picture of is based off of....you follow all that? Either way it gives a place to start.
Ashton