Sayyiduna Anas (may Allah be pleased with him) narrates that there were barely twenty white hairs in the blessed head and beard of the Noble Prophet (peace and blessings be upon him). And Sayyiduna Abu Bakr (may Allah be pleased with him) used to apply a mixture of henna and katam (a plant used as a black dye), and Sayyiduna Umar (may Allah be pleased with him) used only henna to dye his hair.