Choosing a color for the troops

So I'm getting ready to paint my figures for the US Infantry during the Pershing Expedition. I can't quite decide on the color to use. Looking for some thoughts. Here's a shot of the figures painted with one coat of the colors of choice.

the paints are Vallejo 70.880 Khaki Grey, 70.913 Yellow Ochre, 70.879 Green Brown.

Some ideas came from here Wild Bunch For Dummies. I guess I'm leaning towards the Khaki Grey.