Ash-Shama'il Al-Muhammadiyah, Book 5, Hadith 38 (English)

Jaabir bin Samurah R.A. was asked a question regarding the white hair of Rasulullah (Sallallahu alaihe wasallam). He replied: "When Rasulullah (Sallallahu alaihe wasallam) oiled his hair, it (white hair) did not show. When he did not oil it, it showed".

حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، قَالَ‏:‏ أَخْبَرَنَا أَبُو دَاوُدَ، قَالَ‏:‏ حَدَّثَنَا شُعْبَةُ، عَنْ سِمَاكِ بْنِ حَرْبٍ، قَالَ‏:‏ سَمِعْتُ جَابِرَ بْنَ سَمُرَةَ، وَقَدْ سُئِلَ عَنْ شَيْبِ رَسُولِ اللهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّم، فَقَالَ‏:‏ كَانَ إِذَا دَهَنَ رَأْسَهُ لَمْ يُرَ مِنْهُ شَيْبٌ، وَإِذَا لَمْ يَدْهِنْ رُئِيَ مِنْهُ شَيْءٌ‏.‏

also referenced under: Book 5, Hadith 39 (In-Book)