He did not dye his hair, but Abu Bakr and 'Umar dyed their hair.
Sunan Abi Dawud Book 35, Hadith 51
← Previous Hadith I and my father came to the Prophet (ﷺ). He said to a man or to my father: Who is this? He replied: He is my son. He said: Do not commit a crime on him. He had stained his beard with henna.

Sunan Abi Dawud Book 35, Hadith 50 Next Hadith → The Prophet (ﷺ) used to wear tanned leather sandals and dye his beard yellow with wars and saffron, and Ibn 'Umar used to do that too.

Sunan Abi Dawud Book 35, Hadith 52