The Da Vinci Notebooks at sacred-texts.com
Colours seen in shadow will display more or less of their natural brilliancy in proportion as they are in fainter or deeper shadow.
But if these same colours are situated in a well-lighted place, they will appear brighter in proportion as the light is more brilliant.
The variety of colours in shadow must be as great as that of the colours in the objects in that shadow.
Colours seen in shadow will display less variety in proportion as the shadows in which they lie are deeper. And evidence of this is to be had by looking from an open space into the doorways of dark and shadowy churches, where the pictures which are painted in various colours all look of uniform darkness.
Hence at a considerable distance all the shadows of different colours will appear of the same darkness.
It is the light side of an object in light and shade which shows the true colour.