Colours made uniform by shadow; darkness that seems but is not
Chapters 200-202 on how one shadow levels colours and how lit places look dark through interposed air
A text page of the Treatise on Painting closing chapter 200 and giving chapters 201 and 202. It first concludes that a high, remote colour equals a low, near one, since if the high air has lost three quarters of the low air's thickness the rising colour gains three quarters of the whole distance. Chapter 201 holds that all the varieties of colours within one same shadow appear transmuted into the colour of that shadow, as in the darkness of a cloudy night, darkness being nothing but the privation of incident or reflected light. Chapter 202 explains that places in themselves bright can look dark because the illuminated air interposed between the eye and the things seen yields only a uniform obscurity, as with windows viewed from afar.
On this page
High-remote colour equals low-near colour
If the high air has lost three quarters of the thickness of the low air, the colour in rising has gained the three quarters of the whole distance by which it stands remote from the eye. And thus the intent is proved.
Colours transmuted into one shadow (chapter 201)
All the varieties of colours of one same shadow appear transmuted into the colour of that shadow, as in the darkness of a cloudy night where no figure or body-colour is grasped. Darkness is nothing but the privation of incident or reflected light, so when its cause is wholly removed the knowledge of colours and figures fails.
Bright places that seem dark (chapter 202)
Many places, in themselves illuminated and bright, show themselves dark and stripped of all variety of colour and figure. This happens because of the light of the illuminated air interposed between the things seen and the eye, as with windows seen from afar that yield only a uniform, deep obscurity until one enters.