From a page at the The Metropolitan Museum of Art web site:
To understand the lack of color in many Chinese landscape paintings, one must fully appreciate the interrelationship of calligraphy and painting.
Calligraphy and painting use the same formats and tools (brush, ink, paper, and silk). The basic methods of handling a brush and ink to create the individual strokes of a Chinese character can also be used to create descriptive lines and textures in painting.
In this hanging scroll, entitled Woods and Valleys of Mount Yu, by the artist Ni Zan (1306–1374), the correspondence between calligraphy and painting becomes apparent.
Ni Zan, using abstract brushstrokes to suggest three-dimensional forms, exploits the tension between surface pattern and the illusion of recession to animate his composition.
...To see the detail of this painting, follow this link and click on "Open full-size image".