In English, we might call the color above “sky blue,” or perhaps just “light blue.” But in Japanese, it’s not blue at all. It’s its own color: mizu. It's perceived as a unique hue, as GOOD reports, much like we think of red and purple being unique.

Japanese researchers in Tokyo and Kyoto, and Ohio State University researchers in Columbus asked 57 native Japanese speakers to look at color cards and name the colors they saw in order to get a better idea of how many distinct, base colors the Japanese language recognizes. As they write in the Journal of Vision, they found 16 distinct color categories.

The 11 main, base colors named by most participants were equivalent to colors found in the English language: black, white, gray, red, yellow, green, blue, pink, orange, brown, and purple. Others were unique to Japanese, seen as distinct colors in their own right: mizu (meaning “water,” a light blue), hada (meaning “skin tone,” a peach), kon (meaning “indigo,” a dark blue), matcha (a yellow-green named for green tea), enji (maroon), oudo (meaning “sand or mud,” a color we’d call mustard), yamabuki (gold, named after a flower), and cream.

The color terms gathered through the study. The taller the column, the more subjects described the color using that word. (All the colors were named by at least four participants.) Image Credit: Kuriki et. al, Journal of Vision (2017)

 
Mizu, in particular, stood out as a distinct color. While not everyone in the study identified dark blue as kon, mizu was almost universally recognized by the interview subjects. Because of this, the researchers suggest that it be recognized as its own 12th color category in the Japanese lexicon, added to the language's standard color categories of red, blue, green, etc. (the ones that English speakers would find familiar).

The existence of these colors doesn't necessarily mean Japanese is more sensitive to color differences overall compared to other languages—it doesn’t have names for some colors we can identify in English, such as magenta or lime.

“The study of color naming is fundamentally the study of how words come to be associated with things—all things that exist, from teacups to love,” Ohio State optometrist Angela Brown explains in a press release. “The visual system can discern millions of colors,” she says, “but people only describe a limited number of them, and that varies depending on their community and the variety of colors that enter into their daily lives.”

[h/t GOOD]