Did you know that the Japanese word for blue, (青 ao), is sometimes also used to distinguish the color green? The Japanese consider blue to be one of four primary colors that exist (red, blue, white, and black), and the rest of the colors are considered to be various shades of those four colors.

For example, what a westerner would consider to be a green go-signal for traffic lights is sometimes referred to as a blue go-signal to the Japanese. Our western concept of green is a shade of blue to the Japanese. However, modern Japan has a word for green: 緑, midori. This word is used for things that are now more typically referred to as being green in color.