Basing

Trying to decide on the color of the dirt for the bases.  I finished five Night Goblin spearmen with (on the left) darker brown for the rocks and dirt, and the five on the right with a lighter gray-brown color.

Down with the brown, or okay with gray?

Whatever I choose will be used on all the bases for the rest of the Orc & Goblin house army.
The biggest issue is what will the color look like on a large scale with the entire army based that way? The grey color is more subtle and keeps the attention on the figs, where it should be. The brown is very strong and might be distracting, but there's something about it that keeps bringing me back.