Translation guide
The color blue in Japanese is most commonly expressed as 青 (あお). However, Japanese color terms have cultural nuances, especially the historical overlap between blue and green. This guide covers the basic word, shades, idiomatic uses, and common pitfalls.
青
blue (color)
The most common word for blue. Can also refer to green in certain contexts (e.g., traffic lights, young leaves).
Describing something as blue in color.
The i-adjective meaning 'blue'. Used for objects that are blue. Note that 青い can sometimes describe green things, like fresh leaves or vegetables.
空が青い。
The sky is blue.
彼女は青い目をしている。
She has blue eyes.
The noun form 'blue'. Used in compound words or as a standalone color name.
青は私の好きな色です。
Blue is my favorite color.
青信号
green traffic light (literally 'blue signal')
Loanword from English, often used in fashion, design, or to describe a 'blue' mood. Less common for everyday objects.
ブルーのシャツを着ている。
I'm wearing a blue shirt.
今日はちょっとブルーだ。
I'm feeling a bit blue today.
Specifying a particular shade of blue.
Light blue, literally 'water color'.
水色のワンピースが欲しい。
I want a light blue dress.
Navy blue, dark blue. Commonly used for uniforms and formal wear.
Sky blue, a bright light blue.
Lapis lazuli blue, a deep vivid blue. Poetic or literary.
Understanding when 青 refers to green.
Historically, Japanese did not distinguish blue and green as separate colors. 青 covered both. This persists in certain words.
昔、青は緑も含んでいた。
In the past, blue also included green.
Traffic light 'green' is called 青信号 (blue signal).
青信号になったら渡りましょう。
Let's cross when the light turns green.
Describes lush green vegetation, literally 'blue-blue'.
青々とした芝生
lush green lawn
Green apple, though 青 can mean unripe rather than the color.
青りんごの味がする。
It tastes like green apple.
Expressions using blue metaphorically.
The English idiom 'feeling blue' is not expressed with 青い. Use ブルー (casual) or 憂鬱 (ゆううつ, formal) instead.
今日はちょっとブルーだ。
I'm feeling a bit blue today.
Modern Japanese distinguishes blue (青) and green (緑). However, many things that are green in English are still called 青 in Japanese, such as traffic lights, young leaves, and vegetables. When in doubt, use 青 for blue and 緑 for green, but be aware of fixed expressions.
青信号は実際には緑色です。
The 'blue' traffic light is actually green.
紺色のスーツを着てください。
Please wear a navy blue suit.
空色の壁が部屋を明るく見せる。
Sky blue walls make the room look brighter.
A lapis lazuli blue sea stretched out.
He turned pale upon hearing the news.
新事業の青写真を描く。
Draw up a blueprint for the new business.