Translation guide
In Japanese, describing hair as 'blonde' depends on whether it is naturally blonde, dyed, or a specific shade. The most common term is 金髪 (きんぱつ), literally 'gold hair', which often implies dyed or Western-style blonde. For natural blonde hair, especially of children or Caucasians, ブロンド (burondo) is used. Other terms like 茶髪 (ちゃぱつ) refer to brownish or lightened hair, and 銀髪 (ぎんぱつ) to silver/platinum blonde.
The most common way to refer to blonde hair, especially when it is dyed or associated with Westerners.
Literally 'gold hair'. This is the standard term for blonde hair in Japanese, but it often carries a nuance of dyed or artificial blonde, or is used to describe Westerners' hair. It can be used for natural blonde as well, but ブロンド is more precise for natural shades.
彼女は金髪に染めた。
She dyed her hair blonde.
金髪の外国人を見かけた。
I saw a foreigner with blonde hair.
Loanword from English 'blonde'. Used specifically for natural blonde hair, often of Caucasians. It is less common than 金髪 but more precise for natural shades. Can also refer to a blonde person.
彼は生まれつきのブロンドだ。
He is a natural blonde.
ブロンドの髪が太陽に輝いていた。
Her blonde hair shone in the sun.
When the hair is not necessarily platinum or golden blonde, but a lighter brown or bleached shade, often seen in Japanese fashion.
Literally 'brown hair'. Refers to hair that is dyed a lighter brown or reddish-brown, common among Japanese youth. It is not strictly 'blonde' but often overlaps in English descriptions of lightened hair.
茶髪の若者が増えている。
The number of young people with dyed brown hair is increasing.
For very light, almost white or silver blonde hair, often associated with anime characters or fashion.
Literally 'silver hair'. Used for platinum blonde or silver hair, often in fictional contexts or for striking dyed hair.
そのアニメキャラは銀髪だ。
That anime character has silver hair.
金髪 is the default word for blonde hair and can refer to both natural and dyed hair, but it often carries a nuance of being dyed or foreign. ブロンド specifically means natural blonde hair, typically of Caucasians. If you want to emphasize that someone is a natural blonde, use ブロンド. In casual conversation, 金髪 is more common.
彼は金髪だけど、実は染めてるんだ。
He has blonde hair, but actually he dyes it.
彼女はブロンドだから、外国人だと思った。
She's blonde, so I thought she was a foreigner.
The literal translation 黄色い髪 (きいろいかみ) is not used to mean 'blonde hair' in Japanese. It sounds unnatural and may be interpreted as 'yellow-colored hair' like a crayon color. Stick to 金髪 or ブロンド.