白くなった

turned white

→ 白い
phrase Rare #26,448
turned white The past form of 白くなる, meaning that something became white. With hair or a person's head, it commonly means that the hair turned gray or white.
JA: 雪が降って、屋根が白くなった。
EN: It snowed, and the roof turned white.

とともに彼女の髪は白くなった

Her hair turned gray with age.

頭が白くなった

Your hair has gone gray.

— 8 1/2 (1963)

彼の髪は白くなった

His hair turned white.

父の頭は白くなった

My father's hair has turned gray.

彼女は苦労心配のあまり髪が白くなった

The hardships and worries caused her hair to turn gray.