It may be hard to see what’s going on here, but it’s the faint light of the projector on the watercolor paper after I finished drawing. It’s only a small piece of the painting.
Just one layer of the blue sky background in. I think it’s too blue! I used three pigments to make the color more rich: cobalt blue, manganese blue hue and ultramarine violet.
Here’s a corner of the blurry, out of focus parts of the paiting just starting in: