Four Rules of Reflected Colour, and Advice to the Painter
How angle, ray-length, brightness and surroundings govern a reflection's strength
This page of the Treatise on Painting sets out four numbered rules governing how strongly one body reflects its colour onto another: surfaces take a colour most at more equal angles; a shorter reflected ray is more powerful; among equal angles and distances the brighter colour prevails; and an object surrounded only by its own kind of colour reflects most intensely. Two further short chapters add that a reflection built from many objects' colours is more confused, and that the colour nearest a reflection tints it most. Leonardo then turns the physics into practical advice, telling the painter to work into the reflected lights of figures the colour of the nearby garments.
On this page
Four rules for the strength of a reflected colour
Surfaces partake most of the colours reflected at more equal angles; among equal angles, the shorter reflected ray is stronger; at equal angles and distances, the brighter colour is stronger; and an object with only its own kind of colour around it reflects most intensely.
The nearest colour tints the reflection most
A reflection generated from many objects' colours is of more confused colour, while the colour nearest to a reflection tints it most strongly with itself, and conversely.
Advice: reflect nearby garment colours into the figures
Turning the optical principles into workshop practice, Leonardo tells the painter to work into the reflected lights of the figures the colour of the parts of the garments that lie nearest to them.