Blue and Green in Japan

The Japanese word ao (青^?, n., aoi (青い^?, adj.)) can refer to either blue or green depending on the situation.

Modern Japanese has a word for green (緑 midori^?), but it is a relatively recent usage. Ancient Japanese did not have this distinction: the word midori only came into use in the Heian period, and at that time (and for a long time thereafter) midori was still considered a shade of ao. Educational materials distinguishing green and blue only came into use after World War II:^{[citation needed]} thus, even though most Japanese consider them to be green, the word ao is still used to describe certain vegetables, apples, and vegetation.

Ao is also the word used to refer to the color on a traffic light that signals one to "go". However, most other objects—a green car, a green sweater, and so forth—will generally be called midori. Japanese people also sometimes use the word gurīn (グリーン^?), based on the English word "green", for colors. The language also has several other words meaning specific shades of green and blue.