The Prophet ﷺ said, "The Jews and Christians do not dye their hair, so differ from them."
قال النبي ﷺ: إن اليهود والنصارى لا يصبغون، فخالفوهم.
Bukhari related it in the Book of Clothing (5899), and Muslim in the Book of Clothing (2103), both from the hadith of Sufyan bin Uyayna, from Zuhri, from Abu Salama and Sulayman bin Yasar, from Abu Hurairah, who mentioned it.