(24) بَاب اسْتِحْبَابِ خِضَابِ الشَّيْبِ بِصُفْرَةٍ أَوْ حُمْرَةٍ وَتَحْرِيمِهِ بِالسَّوَادِ
Jabir reported that when Abu Qubafa (father of Abu Bakr) came in the yeu of Victory or on the Day of Victory (to the Prophet to pledge his allegiance to him) his head and his beard were white like hyssop. He (the Holy Prophet) commaded or the women were commanded by him that they should change this with something (that the colour of his hair should be changed).
Reference: Sahih Muslim 2102 a
In-book reference: Book 37, Hadith 123
USC-MSA web (English) reference(deprecated numbering scheme): Book 24, Hadith 5243