One word for green and blue

Japanese ao

In older Japanese, ao covered blue and green together. The word midori, now the ordinary word for green, originally referred to fresh growth and became a separate everyday colour term fairly recently. Traces of the older use are everywhere. A green traffic light is called ao shingo. Green apples, fresh leaves and green vegetables are all described with ao. The word also means young or unripe, as green does in English. Japanese green lights are in fact made in a noticeably bluish green, which sits comfortably with the name.

Vietnamese xanh and others

Vietnamese uses xanh for both, and adds a comparison when it matters: xanh lá cây, leaf xanh, for green, and xanh da trời, sky xanh, for blue. Classical Chinese qing covers blue, green and sometimes black, and survives in set phrases alongside separate modern words. Welsh glas traditionally took in blue, the green of grass and some greys. Zulu and Xhosa use one root for both, and specify with like the sky or like grass. Lakota, in North America, has a single word too. The pattern turns up on every inhabited continent.

What it does and does not mean

Having one word does not mean seeing one colour. Speakers of these languages sort and match colour chips as accurately as anyone. What can differ is speed and memory at the boundary: several experiments find that people are slightly quicker to tell two colours apart when their language gives them different names. Schooling, trade and translation tend to split grue over time, and younger speakers often use a newer or borrowed word for one half. Tamil and Hindi, for comparison, have long had separate words for green and blue.

Colours on this page

Sources and further reading

• Blue–green distinction in language on Wikipedia
• Josserand and others, Environment and culture shape both the colour lexicon and the genetics of colour perception (2021)
• BBC Future: The words that change what colours we see