Shama-il Tirmidhi Chapter 16, Hadith Number 2 (108).

Hazrat Amr bin Huraith radiyallahu anhu says, “I had seen Rasoolullah sallallahu alaihe wasallam wear a black turban.”

Commentary.
In Muslim and Nasai, Hazrat Amr bin Huraith radiyallahu anhu says, “That scene is still before my eyes, when Sayyidina Rasoolullah sallallahu alaihe wasallam was delivering the sermon on the mimbar. He wore a black turban on his auspicious head, and its shamlah (the end portion of the turban) was between his shoulders.