On Vision and Colors & Color Sphere

For Schopenhauer, vision is wholly subjective in nature and characterized by processes that cross over into the territory of philosophy. 

Runge's Color Sphere and essay "The Duality of Color" contained one of the first attempts to depict a comprehensive and harmonious color system in three dimensions. Runge intended his color sphere to be understood not as a product of art, but rather as a "mathematical figure of various philosophical reflections." 

By bringing these two visionary color theories together within a broad theoretical context—philosophy, art, architecture, and design—this volume uncovers their enduring influence on our own perception of color and the visual world around us.