أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ الأَعْلَى، قَالَ حَدَّثَنَا الْمُعْتَمِرُ، قَالَ سَمِعْتُ كَهْمَسًا، يُحَدِّثُ عَنْ عَبْدِ اللَّهِ بْنِ بُرَيْدَةَ، أَنَّهُ بَلَغَهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏"‏ إِنَّ أَحْسَنَ مَا غَيَّرْتُمْ بِهِ الشَّيْبَ الْحِنَّاءُ وَالْكَتَمُ ‏"‏ ‏.‏

It was narrated from 'Abdullah bin Buraidah that: He heard that the Messenger of Allah [SAW] said: "The best things with which you can change gray hair are Henna and Katam." Translation Not Available

Book Ref: Sunan An Nisai Book 48 Hadith 5082
Web Ref:  Sunan An Nisai Vol 6 Book 48 Hadith 5085