Thinking about how to make Fauvism work in watercolour I came across these by Andre Derrain and Raul Dufy.
Painting with expressive lines and colour is something that had been brewing since Van Gogh and Gaugin. In watercolour the white of the paper, that remains visible in drawing, helps to keep our colours vibrant.
Colour has also become a more expressive vehicle that is moving ever closer to abstraction. (Matisse below)