I was at the local art store this past weekend and picked up a tube of Prussian Blue and Flake White. I'm surprised at the strength of the Prussian Blue and I'm also surprised at the transparency of the Flake White. I made sure I washed my hand really well after this session because the Flake White had a serious cancer warning on the back. Yikes!
I plan to have one more session on this painting before I finish. I'm pleased with the results so far. The next session I will try to darken the shadows, draw out the highlights, interject light green areas into that grassy stuff up close, at the bottom, and put more character and age on those old bricks.