COLOUR. — The term "colour" refers both to the sensation produced by matter permeated by a light that determines a "quality" in it, and to the light itself that defines such a quality. In art, colour is one of the elements of the language of figurative art, and as such it contributes to constituting the very essence of the work of art, participating in it in various ways with the other elements, according to the stylistic requirement that guided the artist’s creation.
The pictorial properties of colour are quality, intensity, and tone. Quality is the distinction of matter within the luminous spectrum (e.g., red, yellow, blue, etc.); intensity is determined by the greater or lesser distance from the qualities of neutrals; tone is the fusion of matter and light, or rather the value that a given colour acquires depending on the amount of light it absorbs and reflects.
By neutrals are meant those gradations of greys, from white to black, which, lacking in light, implicitly negate colour.
The history of art unfolds through these properties, with the varied alternation of expressive means designed to evoke luminous or chromatic sensations.
In fact, to the properly so-called tone, which was a recent achievement in modern painting (it is well known how the name of Giorgione [1480–1510] is linked to "tone"), the chiaroscuro (q.v.) stands opposed, having a more ancient tradition (it was Masaccio who first fully understood its possibilities); it is based on the gradations of neutrals that are superimposed on pure colours to create shadow effects, contrasting with the light effects suggested by them. In contrast, tone is achieved through the succession of colour qualities in relation to light and shadow (for example, a light yellow and a dark violet, combined to create respectively the light area and the adjacent shadow area).
Entirely different was the stylistic vision of Leonardo da Vinci, who opposed the use of colour tones with the gradations of neutrals, blended in their chiaroscuro (q.v.). Thus, the predominant shadows in his pictorial ideal, distancing themselves from the richness of colour, delineated one of the most suggestive and poetic attitudes in Western painting.