The Beauty of Color Lies in Its Illuminated Parts
With a small diagram showing how light bounced from a red surface tints an adjacent face.
This page of the Treatise on Painting holds four short chapters on color and light, together with a small pen diagram set into the text. The text argues that every color is most beautiful where it is lit, since light gives true knowledge of its quality while shadow deadens it (adding that black and white are not truly colors), and that brighter things are seen farther off than dark ones. Using the lettered diagram, chapter [209] shows how light thrown from an illuminated red surface tints an adjacent face and can create a shifting color between yellow and red. It closes by urging the painter to show the true colors on the lit parts, and opens the heading on green made from copper rust.
On this page
Color is most beautiful where it is lit; black and white are not colors
The opening states that every color is more beautiful in its illuminated part than in shadow, because light vivifies and gives true knowledge of a color's quality while shadow deadens and darkens it. If black seems more beautiful in shadow than in light, the answer given is that black is not a color, nor is white. Chapter [208] adds that the brighter a thing is, the more it appears from a distance.
Diagram: light reflected from a red surface tints an adjacent face
Chapter [209] uses a lettered figure: let a be the light, b the part illuminated along a line from it, and c a point that cannot see the light and sees only the illuminated part, which is red. The light cast to the part resembles its cause and tints the face c red; if c is itself red it is even more beautiful than b, and if c were yellow a shifting color arises between yellow and red. A small pen diagram carries the lettered points.
Show the truth of colors upon the illuminated parts
Chapter [210] reasons that since the quality of colors is known by means of light, the true quality is seen most where there is most light, and where there is more darkness the color takes on the color of that darkness. It therefore reminds the painter to show the truth of colors on the illuminated parts. A final heading opens the topic of the green color made from the rust of copper.