I thought I read somewhere that the material used in the editor affects the terrain to a degree...
For example the "dirt" material kicks up dust as you drive across it, but the "soil" material doesn't (don't quote me on that lol).
I still don't think I quite have a handle on the "tint" aspect aside from it making the dirt look darker...
For a first step, it would be good if there were sand colored mud textures. I use about <0.6 mud extrudes for sand, too. But when you drive over this sand you get dark brown tracks and that looks wired.
As sand is not so very importand in the world of Mudrunner, I would prefer snow and ice + its physics over new sand physics.