Musnad Ahmad 33:287

Isma'il narrated to us, Layth informed us, from Abu al-Zubayr, from Jabir, who said: Abu Quhafa was brought on the day of the Conquest to the Prophet, may Allah bless him and grant him peace, and his head was as if it were *thughama* (a white plant). The Messenger of Allah, may Allah bless him and grant him peace, said: "Take him to some of his wives, so let her change it with something, and avoid black for him."