Hazrat Ubayy (ra) was of moderate height. The colour of his hair and beard was white and he did not dye them in order to conceal his grey hair. He did not dye his beard nor his hair.
(Ibn Saad, Al-Tabaqat al-Kubra, Vol. 3 (Beirut, Lebanon: Dar al-Kutub al-Ilmiyyah, 2017) 378)