The Middle Ground Color Block-In
Beginning with the large middle mountain, I put in the shadows with a purple green-gray. I added yellow ochre and white for the lighter areas, being very careful not to get this area too warm. White is a cool color, and I premix a puddle of white tinged with yellow for just this kind of use. Since there is so much blue-gray in the atmosphere, all colors are affected by it.
As I came toward the foreground, I added more yellow ochre and yellow, and reduced the amounts of gray. The warm reddish field on the left-hand hill is cadmium red light with thalo blue and white. The very light grassless areas in the middle ground are orange and white, grayed with a bit of ultramarine blue. At the edge of the river, I changed the water edge to a small bank made with cadmium red light, thalo blue and white. The darks in the grass, the cast shadows, and the shady sides of the trees are various shades of green darkened with blue-violet.
The trunk of the tall left-hand skinnty tree needs more variety. The top is interesting, but the rest of it is too straight.