Complementary Colors, the Medium, and the Blue of Mountains
Direct opposites, how air and glass transmute color, and why distant mountains look blue
This page lists direct-opposite (complementary) pairings — pale with red, black with white, blue with gold-yellow, green with red — and notes that a white object in dark, turbid air looks larger than it is. It explains that the medium between eye and object dyes the object with its own color: blue air turns distant mountains blue, red glass reddens all beyond it, and the darkness of night swallows the halo around the stars. Paragraphs marked a, b and c then state that every color reads best against its contrary, define a body's 'true' color as the part free of shadow and highlight, and begin the rule that a distant mountain looks bluer the darker and more wooded it is. Text only, headed SECVNDA, foliated 77.
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Direct-opposite (complementary) color pairs
A direct opposite is pale with red and black with white — though neither black nor white is truly a color — blue with yellow like gold, and green with red. A white object seen in dark, turbid air (marked a) appears larger than it is, because a bright thing grows against a dark ground.
The medium transmutes the color of what is seen
Marked b, the passage states that the medium between eye and object changes the object into its own color: blue air makes distant mountains look blue, red glass reddens everything beyond it, and the darkness of night occupies the light around the stars. Every color, it adds, is known better against its contrary than against its like.
The true color of a body and the blue of mountains
A body's true color shows in the part touched by neither shadow nor highlight, if the body is polished. A mountain distant from the eye looks a more beautiful blue the darker it is in itself, and it is darker the higher and more wooded it is.