The colors we see in the world aren't only a function of our eyesight. The language we speak can impact the colors we recognize, as Lancaster University researchers Aina Casaponsa and Panos Athanasopoulos explain on The Conversation.

The number of words a given language has for colors can vary widely, from only a few—the Bassa language, spoken in Liberia, has two terms, one for the warm end of the color spectrum and one for the cool end—to languages like English (up to 11 terms) and Japanese (16 terms, as a 2017 study found).

Researchers have even proposed a hierarchy related to which colors a language names depending on the total terms it has. If a language only has two terms, they are almost always related to black and white (dark and light). If they have three, that third color is almost always red. And so on into green, yellow, and blue.

Which colors have names in a particular language influences the colors we see. Japanese, Russian, and Greek, for instance, include terms that differentiate between light blue and dark blue. While an English speaker might look at a sky blue shirt and a navy blue shirt and say, "Look, a pair of blue shirts!" a Japanese speaker would disagree, just as we might disagree with someone who speaks Bassa about whether red, orange, and yellow are all one color. However, if you spend enough time immersed in a language that has fewer color terms, it appears that the way you describe color may narrow—according to one study, Greek speakers who spend a lot of time in the UK tend to stop distinguishing between two different blues, ghalazio and ble, and begin lumping them into a single category of blue.

The impact goes beyond shirts, of course. While modern Japanese has two distinct words for blue and green, Old Japanese had one term for both of them, ao. This historic link between the two colors still exists in some uses. Japanese stoplights use ao as the color for "go"—meaning that sometimes, they use blue instead of green. Several other languages historically had one term that can refer to either green or blue—what linguists call "grue"— including Vietnamese, Welsh, and Pashto.

It seems that in general, we are better at distinguishing between warm colors like red and yellow than cool colors like blue and green. In an October 2017 study, cognitive scientists found that across languages and cultures, people tend to find it easier to communicate about warm colors than cool when given a grid of colored chips. The researchers hypothesized that the colors we are able to describe have to do with what's important to us: "Objects (what we talk about) are typically warm-colored, and backgrounds are cool-colored." They also suggested that the reason some languages develop more color words than others has to do with industrialization.

After studying Bolivian Spanish speakers, the Amazonian hunter-gatherer group called Tsimane' that has relatively few color categories, and English speakers in Boston, researchers found that the Tsimane' people did not often describe familiar natural objects (like, say, an unripe banana) using color, but they used more color words to describe artificially colored objects (like a red cup). Industrialization, they hypothesized, increases how useful language for color is, since the only way to distinguish between certain objects (plastic cups, for instance) might be by their color.

[h/t BBC]