Musannaf Ibn Abi Shayba 16:394

Abu Bakr narrated to us, he said: Abu al-Ahwas narrated to us, from Abu Ishaq, from al-Aizar ibn Hurayth, who said: I saw al-Husayn ibn Ali, and upon him was a garment of silk (khazz), and he used to dye [his hair/beard] with henna and katam.