In the sketch of the library in Millbrook, New York, I observed plenty of bluish color in the cast shadows on the sidewalk, for example.
But planes in shadow that face downward are different because they pick up the warm reflected color of illuminated surfaces below them. You can see this effect in the white pediment. Where the projecting forms faced downward, they’re distinctly orange, not blue at all.
So let’s revise that quick rule of thumb about the color of shadows: “In shadows, upfacing planes are cool, and downfacing planes are warm.“ If you click on the photo above, taken at Bryce Canyon by Tobey Sanford, you can see the cool upfacing planes (1), and the warm downfacing planes (2). What you can't see are my knees shaking.
Tomorrow: Baseball Cap Space Helmet