Hadith 1637

Jabir (May Allah be pleased with him) said: Abu Quhafah, father of Abu Bakr (May Allah be pleased with them) was presented to the Messenger of Allah (PBUH) on the day of the conquest of Makkah and his head and beard were snow white. The Messenger of Allah (PBUH) said, "Change it (i.e., dye it and avoid black colour)."

[Muslim].