Sunan an-Nasa'i, Book 48, Hadith 37 (In-Book)

It was narrated that Jabir said: "Abu Quhafah was brought on the Day of the Conquest of Makkah, and his hair and beard were white like the Thaghamah. The Messenger of Allah [SAW] said: 'Change this with something, but avoid black.'"

أَخْبَرَنَا يُونُسُ بْنُ عَبْدِ الأَعْلَى، قَالَ حَدَّثَنَا ابْنُ وَهْبٍ، قَالَ أَخْبَرَنِي ابْنُ جُرَيْجٍ، عَنْ أَبِي الزُّبَيْرِ، عَنْ جَابِرٍ، قَالَ أُتِيَ بِأَبِي قُحَافَةَ يَوْمَ فَتْحِ مَكَّةَ وَرَأْسُهُ وَلِحْيَتُهُ كَالثَّغَامَةِ بَيَاضًا فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ غَيِّرُوا هَذَا بِشَىْءٍ وَاجْتَنِبُوا السَّوَادَ ‏" ‏ ‏.‏

sunnah.com