A Little Book on Colors

Uncertain colors.

There are also some colors that are uncertain, which deceive the eyes of those looking at them, such as the luster of the sky, which, while some assume it to be dark, when illuminated by solar rays appears blue, as does the rainbow, or the clouds that we see from below sometimes igniting, or the sea itself, which, besides blue, sometimes bristles as black, sometimes grows green, at times also presents itself as yellow or grey, or appears purplish with a certain aspect. Nor is the same elegance observed in the neck of the dove and the peacock; whence birds are often called "variegated," such as a well-known type of silk which, when viewed from different parts, does not offer the same charm of color.
Discolor

Furthermore, discolor (variegated) is used not only for what is varied, but if something spreads the same color like certain rays, as

Decolor

But he is called decolor (discolored) from whose face the color has drained away and who has been left bloodless, and for that reason it is taken as deformed and black, as "the decolor Indian"—for no one is ignorant that concolor (same-colored) means being of the same color. Furthermore, colors are divided in two ways; for all the rest, except for minium (red lead), purpurissum (imitation purple), cinnabaris (cinnabar), armenius (armenium), chrysocolla (gold solder), and indicum (indigo), were called austeri (harsh/austere), while the latter they called floridi (bright/flowery). But let the painters see to these matters, for whom in former times only melinus (quince-yellow) color, candidus (white), silaceus (pale yellow, which is numbered among the blue-greens), a kind of red earth called sinopis, and atramentum (ink) were in use. Some are also called suaves (sweet/pleasant), such as flauus (yellow), purpureus (purple), candidus (white), and especially roseus (rose-colored); and to human eyes nothing seems more pleasant than the color of a beautiful person. That there is indeed a pleasantness in colors, besides the fact that the senses themselves judge it...