There are all sorts of combinations that one could use. Here's one that I still have the recipe written down used some for Second Anglo Afghan War Brits but the recipe could easily be modified to adjust for variation.
I used on following these chaps:
First three Stages are all AK AK Brush and Airbrush (Water based Acrylic)-1/ Basecoat of AK Brush and Airbrush (Water based Acrylic)- WWI British Khaki Brown Base- AK4042
2/ Mix of WWI B. K. B. B.- AK4042 with AK Brush and Airbrush WWI British Uniform Light
3/ WWI British Uniform Light
Then a mix of AK Brush and Airbrush (Water based Acrylic) and Vallejo Pale Sand- small amounts of Pale Sand added to start with and building up as you progress until you arr satisfied with the result.
I used about seven layers up to the final highlights but the recipe could very easily be distilled down to just a few layers over the base coat.
Hope that helps? I've got a good Vallajo Khaki recipe that I have written down in a different note book which I can dig out for you if you like?

