A correspondent has taken me gently to task about my use of words to describe the attributes of colour. He points out that I used hue in the sub-title of my article about colour words almost as a synonym for colour. He doesn’t think that’s correct. This provoked me to delve a little deeper into words describing attributes of colour rather than the colours themselves.
The word hue is actually a slippery word to define and understand and has anyway subtly changed its sense down the centuries (it has no connection, by the way, with the word which turns up in the set expression hue and cry, which comes from the old French huer, “to shout”; our hue comes from the Old English word meaning “form, appearance”). Up to about the sixteenth century it was used virtually as a synonym for colour, but then seems rather to have gone out of fashion except in elevated writing. In modern usage it frequently means much the same as colour (the first sense both in the Concise Oxford Dictionary and Chambers’ 21st Century Dictionary is given as “colour, tint or shade”) though with a sense, more precise than that of colour, of focusing on subtle variations between shades of colour.
But hue also has a much more tightly defined and technical meaning which derives from attempt to define colours unambiguously. This is not an easy task — it was only in the 1730s that the first systematic theory of colour was worked out, by the German Le Blon. Since then dozens of people have attempted to formalise colour descriptions so they can be accurately and consistently reproduced, the first being Moses Harris, who in 1776 published the first proper colour wheel. In one of the best known of these — the Munsell system (invented by the American Albert Munsell) — hue is used to describe one of the attributes of a colour, “that attribute ... by which it is recognised as a red, a purple, a green, etc, and which approximately corresponds to its dominant wavelength”, to quote the OED’s definition.
Dictionary-makers have a lot of trouble with such technical terms, because within the limitations of the few words available (the OED’s definition is verbose by lexicographical standards) it is often almost impossible to give a definition that is precise enough to satisfy the technical reader but which the non-technical reader will understand. The Concise Oxford essays “the attribute of a colour by virtue of which it is discernible as red, green, etc”, a cut-down version of its big brother’s definition. But compare it with the definition from its Chambers’ equivalent: “the feature of a colour which distinguishes it from other colours”, which is pretty well meaningless. The Random House Webster’s Unabridged has “the property of light by which the color of an object is classified as red, blue, green, or yellow in reference to the spectrum”, which might suggests to the unwary reader that hue only characterises those four colours. The most precise definition I’ve come across is — not surprisingly — in the Chambers Science and Technology Dictionary: “The perception of colour which discriminates different colours as a result of their wavelengths” (perhaps Chambers’ various departments should get together sometime?).
In several of these modern colour defining systems, there are two other vital attributes of a colour. One is variously called saturation or chroma (roughly how intense the colour is, or more formally how much it departs from white or grey; chroma was not first used by Munsell but he almost certainly independently reinvented it, based on the Greek word meaning “colour”). The other was vaguely just called value in the original Munsell system, and corresponds to what we commonly describe as brightness; nowadays it tends to be called luminance, a comparatively new term from physics based on the Latin luminare, “to illuminate”. A different system compares the colour with the three primary colours of red, green and blue and creates a chromaticity diagram, which you can call a colour triangle if you dislike that word chromaticity, first used only in 1922 (if you use Microsoft Windows, you will have seen both systems in the charts used to set display colours).
I’ve been throwing about some other words which seem to have obvious and clear meanings but which deserve to be investigated a bit more. Take shade. This actually has several meanings, principally that of “partial darkness; a state of being sheltered from direct light”, but it is also used commonly in a sense which is very close to that of the more formal word chroma, “the degree of darkness or depth of colour within one hue”. Painters have long used the word in a related sense of a mixture of a colour with black, so a shade is a colour which has been made darker in this way. They oppose it with tint, which is the opposite process of adding white to a colour, to desaturate it.
Interestingly, my British dictionaries all give this as the principal sense of tint with the other senses of “a slight admixture of another colour” (as in “it’s red with a slight blue tint”) or “a pale or faint colour used as a background” only secondarily. They also say that the word only came into the language in the early 1700s, derived from the older word tinct — from Latin tinctus, “to dye”, which has also given us tincture, “colouring matter” and tinge — but which may have been influenced by the Italian tinta.
Have I cast a new light on the subject?