YOU SAID:

A man so black his skin is purple.

INTO JAPANESE

肌が真っ黒な人は紫色です。

BACK INTO ENGLISH

People with black skin are purple.

INTO JAPANESE

黒い肌の人は紫色です。

BACK INTO ENGLISH

People with dark skin are purple.

INTO JAPANESE

肌の色が濃い人は紫色です。

BACK INTO ENGLISH

People with dark skin are purple.