This is a piece from an untitled series of ten large flowers by Hokusai.

The hydrangea is native to Japan, and any Japanese would recognize this flower. Similarly, the swallow is a common migratory bird seen during the summer, familiar to most Japanese.

Hokusai depicted the shapes of both subjects very realistic, especially the flying swallow, showing his astonishing observational skill. But what about the colors?

The colors of a hydrangea are known to vary with soil acidity; acidic soil turns it blue, alkaline soil produces red, and neutral soil results in purple. In this image, we see gentle shades of pink and blue are mixed. Is this realistic? Yes, certain types of hydrangea change color as the flower matures.

It is very interesting that while Hokusai chose very mild colors for the flowers and the swallow's neck, he used very strong blacks and greens for the leaves and the bird's feathers. We think that this contrast creates a very attractive and striking effect.