Among the three major comic styles in the world (Japanese Manga, European Comic Strips, and American Comics), using Black and White to convey subjects is a defining characteristic of Japanese manga.
Japanese manga originated from Katsushika Hokusai's "Hokusai Manga" and is derived from Ukiyo-e. The manga that developed from this tradition inherited the unique “lineworks” and “negative space” which can be found in Ukiyo-e.
The term "Ukiyo" means "the present world" or "the world in flux," and Ukiyo-e, as the name suggests, refers to artworks created by Edo(Japanese period) artists using popular painting techniques to depict the social landscape of that time.
The Japanese manga that developed from this tradition is defined as "Contemporary Ukiyo-e," portraying the contemporary social landscape.