This was my too dark dirt colored paint on the upper level. Ballast here is gravel (de-iron particled) and tile grout.  Trying to represent the dirt between
the ties in a mountain ROW, I tried dirt - but could never find the right texture; sanded grout - but it was too uniform in color and texture.
  This is one aspect I am not happy with, and the search will continue for a better method before the next layout. 
Maybe if I can find the right fine light-colored dirt that looks good sifted and filtered with no clay or silt....