Arthur Schopenhauer proposed a theory of colour as a consequence of his first hand knowledge of J.W. Goethe’s experiments with color phenomena. This colour theory can be used to explore an interesting proposition Schopenhauer made about architecture. For Schopenhauer, architecture is about feelings, not about functions or forms, its purpose as an art is to reveal the principles of primitive forces, specifically gravity and rigidity. For Schopenhauer, architecture expresses these forces in the poised equilibrium of massive structures built out of stone. Schopenhauer was inclined to believed that architecture had already achieved its most perfect expression in Greek temple architecture. However; he did offer one possibility for architectural research: this was the suggestion that architecture was also concerned with the expression of light. It seems never to have occurred to Schopenhauer to use his colour theory to speculate about light in architecture. This paper explores some of the implications of Schopenhauer’s theory of colour for his aesthetics of architecture?