Brightening the Vista...

Using emerald blue and stippling, layer over the trees, adding light green where lit...  where the next round of vegetation was, stippled first the light green on the unshaded area, then layered the emerald green over the whole...  the rock was first layered with red earth on the shade areas, then raw sienna for the rest, then a layering of flame orange stripped here and there across the sunlit areas...

Note that there is a small bit of white left around most of the grass blades in front of the section rock greens - deliberately so to pull the grasses forward more by giving space between the foreground and that section...