أَخْبَرَنَا حُمَيْدُ بْنُ مَسْعَدَةَ، قَالَ حَدَّثَنَا عَبْدُ الْوَارِثِ، قَالَ حَدَّثَنَا الْجُرَيْرِيُّ، عَنْ عَبْدِ اللَّهِ بْنِ بُرَيْدَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ إِنَّ أَحْسَنَ مَا غَيَّرْتُمْ بِهِ الشَّيْبَ الْحِنَّاءُ وَالْكَتَمُ ‏"‏ ‏.‏

It was narrated that 'Abdullah bin Buraidah said: "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 5081
Web Ref:  Sunan An Nisai Vol 6 Book 48 Hadith 5084