I frequently have problems with cerulean blue. It is the coverage; I have to use quite a lot of pigment to get a decent tone on the paper. However, with cerulean blue deep, the problem goes away. The color is shown on the study below. It is a rich deep blue. It goes rather well with the gamboge yellow. I particularly like the green tendrils that arise at the border between the blue and the yellow. The gamboge doesn’t mix as well with the quinacridone burnt orange that abuts the lower edge of the yellow field.
I mixed a bit of the gamboge with the blue at the upper left corner, which resulted in a grainy greenish hue. The watery application of cerulean blue deep at the bottom has quite a different character than the saturated blue arc at the top of the composition.
Cadmium red light book-ends this design and completes the triad of primary colors in this piece.