It is narrated from Hazrat Anas (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) never applied dye. There were a few white hairs in the front part of his beard, above the chin, in his head, and on his temples, which were not very noticeable.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 13809
Hadith Gradingحکم دارالسلام:إسناده صحيح، م: 2341، وانظر لزاما: 12054 وتطبيق النووي بين الأحاديث فى خضاب النبى صلى الله عليه وسلم وعدمه