Colour Words Divide The Spectrum Differently

The spectrum is continuous and colour vocabulary is not. Where a language puts its boundaries is a decision, and different languages have made different ones.

Basic terms and the rest

Linguists distinguish basic colour terms from the many words that describe a shade by reference to something else. A basic term is short, general and not a subtype of another colour.

By that definition every language has a limited set, and the sets vary widely in size. Some have a handful, others a dozen or more, and none have hundreds.

Words for particular dyes, materials and animals sit outside the set. They are precise but they behave differently in the grammar and speakers treat them as descriptions rather than colours.

The order in which terms appear

Comparative work found that small colour vocabularies are not random. Languages with only two basic terms divide light from dark, and the third to appear is almost always a red.

After that the usual additions are a green or yellow, then blue, then brown, and then the remaining terms in a less fixed order.

The regularity suggests the divisions are not arbitrary even though the boundaries are. Something about human vision makes certain divisions more useful and more likely to be made first.

The blue and green boundary

A single term covering both blue and green is common across unrelated language families, and speakers of such languages see the difference perfectly well.

Where a separate blue term later appears, it often arrives with a dye, a pigment or a trade good that made the distinction worth marking regularly.

Splitting a term does not erase the old one. The parent word usually narrows to one side while a newer word takes the other, which leaves traces in older texts and idioms.

What the boundary does to attention

Careful experiments suggest speakers are slightly faster at telling apart two shades that their language names differently. The effect is real and it is small.

It is a matter of speed and categorisation rather than perception. Nobody is unable to see a difference, but the boundary makes some comparisons quicker to make and to describe.

The effect weakens when the task occupies the language faculty, which suggests the words are being used as a shortcut rather than altering the eye.

Where the words come from

Colour terms are frequently traceable to things. Words for orange, violet and many browns started as the name of a fruit, a flower or a material and generalised.

That path is still visible in newer terms. A colour word that entered a language recently usually still has its source object attached in ordinary use.

Older basic terms have lost their origins entirely, which is part of what makes them basic. When nobody can remember what a colour word once referred to, it has finished becoming abstract.