How the Air Takes On the Colours Behind It
Distant mountains turn blue; which colours shift toward blue at a distance
A text page of the Trattato della pittura (folio 73 verso) on aerial colour perspective. Leonardo argues that air has no smell, taste, or colour of its own but takes on the likenesses of things behind it, appearing a more beautiful blue the greater the darkness behind it, as seen in distant shadowed mountains. Two short chapters follow: colours nearest to black shift toward blue most over distance (green of fields more than yellow, white, or red), and colours placed in shadow keep more or less of their natural beauty according to the depth of the darkness, showing greater beauty in a more splendid luminous space. The page ends mid-argument with an 'Adversary' objection and 'Reply'.
On this page
Air takes on the colours of what lies behind it
The air in itself has no smell, taste, or colour, but receives the likenesses of the things placed behind it, and is a more beautiful blue the greater the darkness behind it, provided it is not too spacious or too thick with moisture. Shadowed mountains appear a more beautiful blue at long distances; where more illuminated they show the mountain's own colour rather than the blue lent by the intervening air.
Which colours turn blue with distance (g)
Among non-blue colours, the one nearest to black partakes most of blue over a long distance, while the colour most unlike black best keeps its own hue. Thus the green of the fields changes into blue more than yellow or white does, and yellow, white, and red change least.
Colours in shadow versus in a luminous space (h)
Colours placed in shadows keep more or less of their natural beauty according to whether the darkness is lesser or greater. Set instead in a luminous space, they show themselves the more beautiful the greater the splendour of that light. The chapter closes with an Adversary's objection that shadow-colours are as varied as the colours of the shadowed things, followed by an unfinished Reply.