Green Apples, Blue Apples - Color Perception in Japanese


The human eye is capable of perceiving an astonishing number of different color shades. However, when describing a particular color, we are inevitably restricted by the boundaries of the language we speak. As children, we are taught how to name colors according to the generally accepted paradigms in our culture. Nevertheless, it is not entirely unusual for two different individuals to sometimes use different expressions when referring to the exact same shade. That might be because each individual attributes a broader or narrower spectrum to a particular shade. For instance, what I perceive as darkish pink may look like purple to somebody else.
Moreover, discrepancies between the ways people interpret the color spectrum in linguistic terms can also be seen on a cross-cultural level. For instance, some languages spoken in Namibia and Papua New Guinea do not have separate expressions for "green" and "blue" but use the same word to denote both colors (Casaponsa, Athanasopoulos, 2018).
And these are not the only languages where the lines between blue and green seem to be somewhat blurred. In modern Japanese, the word for blue is "ao" and the word for green is "midori." For instance, you would use "ao" to describe the color of the sky and "midori" to describe the color of grass.
Before the Heian period (more than a millennium ago), the Japanese language actually utilized the word "ao" to refer to a rather wide spectrum of colors - it was used to denote what the English language describes as both "blue" and "green" (ITmedia NEWS, 2017).
As mentioned above, "ao" and "midori" in modern Japanese are in most cases equivalent to "blue" and "green" in English. Still, the historically vague linguistic distinction between these two shades has apparently been preserved to the present day in certain expressions.
Arguably the most well-known example is the color of the light that allows traffic to proceed. In many parts of the world, that color is referred to as "green," yet in Japan it is called "ao" (blue). Green apples are another example of this phenomenon - in Japanese they are called "aoringo" or (literally) "blue apples." A kind of healthy beverage made from kale and other vegetables is called "aojiru" or "blue juice" even though its color is normally green.
After some online research, I was able to create a list of Japanese "blue" nouns that refer to green things.




green traffic light


green apple


green juice


green leaf


green caterpillar


green laver


green bamboo log


green as in "inexperienced"

As you can see in the table above, many "blue" nouns denote green plants or animals. The last entry on the list, "aoi," can be used metaphorically to refer to an inexperienced person - or even unripe fruit.
Nowadays, the green-blue contrast mostly follows the standard pattern. Still, this semantic overlap of the word "ao" provides an interesting glimpse into the history of the Japanese language.


1) Casaponsa, Aina, Athanasopoulos, Panos. (Apr 16, 2018). The way you see colour depends on what language you speak. Retrieved from (accessed April 2, 2020)

2) ITmedia NEWS.(2017年3月3日)「青々とした緑?」青と緑は歴史の中で"分離"した-東北大など調査.年4月2日閲覧)