Volume 4 · Book 56 · Hadith 750
Narrated Qatada: I asked Anas, "Did the Prophet use to dye (his) hair?" He said, "No, for there were only a few white hairs on his temples."
— Sahih Bukhari, Volume 4, Book 56: Virtues and Merits of the Prophet (pbuh) and his Companions, Hadith #750