He did not dye his hair, but Abu Bakr and 'Umar dyed their hair.  

عَنْ خِضَابِ النَّبِيِّ ﷺ فَذَكَرَ أَنَّهُ لَمْ يَخْضِبْ وَلَكِنْ قَدْ خَضَبَ أَبُو بَكْرٍ وَعُمَرُ ؓ   

The Prophet ﷺ used to wear tanned leather sandals and dye his beard yellow with wars and saffron, and Ibn 'Umar used to do that too.  

أَنَّ النَّبِيَّ ﷺ كَانَ يَلْبَسُ النِّعَالَ السِّبْتِيَّةَ وَيُصَفِّرُ لِحْيَتَهُ بِالْوَرْسِ وَالزَّعْفَرَانِ وَكَانَ ابْنُ عُمَرَ يَفْعَلُ ذَلِكَ  

When a man who had dyed himself with henna passed by the Prophet ﷺ, he said: How fine this is! When another man who had dyed himself with henna and katam passed by, he said: This is better than that. Then another man who had dyed himself with yellow dye, passed by, he said: This is better than all that.  

مَرَّ عَلَى النَّبِيِّ ﷺ رَجُلٌ قَدْ خَضَبَ بِالْحِنَّاءِ فَقَالَ مَا أَحْسَنَ هَذَا قَالَ فَمَرَّ آخَرُ قَدْ خَضَبَ بِالْحِنَّاءِ وَالْكَتَمِ فَقَالَ هَذَا أَحْسَنُ مِنْ هَذَا قَالَ فَمَرَّ آخَرُ قَدْ خَضَبَ بِالصُّفْرَةِ فَقَالَ هَذَا أَحْسَنُ مِنْ هَذَا كُلِّهِ  

The Prophet ﷺ said: At the end of time there will be people who will use this black dye like the crops of doves who will not experience the fragrance of Paradise.  

قَالَ رَسُولُ اللَّهِ ﷺ يَكُونُ قَوْمٌ يَخْضِبُونَ فِي آخِرِ الزَّمَانِ بِالسَّوَادِ كَحَوَاصِلِ الْحَمَامِ لاَ يَرِيحُونَ رَائِحَةَ الْجَنَّةِ  

When the Messenger of Allah ﷺ went on a journey, the last member of his family he saw was Fatimah, and the first he visited on his return was Fatimah. Once when he returned from an expedition she had hung up a hair-cloth, or a curtain, at her door, and adorned al-Hasan and al-Husayn with silver bracelets. So when he arrived, he did not enter. Thinking that he had been prevented from entering by what he had seen, she tore down the curtain, unfastened the bracelets from the boys and cut them off. They went weeping to the Messenger of Allah ﷺ, and when he had taken them from them, he said: Take this to so and so's family. Thawban. In Medina, these are my family, and I did not like them to enjoy their good things in the present life. Buy Fatimah a necklace or asb, Thawban, and two ivory bracelets.  

عَنْ ثَوْبَانَ مَوْلَى رَسُولِ اللَّهِ ﷺ قَالَ كَانَ رَسُولُ اللَّهِ ﷺ إِذَا سَافَرَ كَانَ آخِرُ عَهْدِهِ بِإِنْسَانٍ مِنْ أَهْلِهِ فَاطِمَةَ وَأَوَّلُ مَنْ يَدْخُلُ عَلَيْهَا إِذَا قَدِمَ فَاطِمَةَ فَقَدِمَ مِنْ غَزَاةٍ لَهُ وَقَدْ عَلَّقَتْ مِسْحًا أَوْ سِتْرًا عَلَى بَابِهَا وَحَلَّتِ الْحَسَنَ وَالْحُسَيْنَ قُلْبَيْنِ مِنْ فِضَّةٍ فَقَدِمَ فَلَمْ يَدْخُلْ فَظَنَّتْ أَنَّ مَا مَنَعَهُ أَنْ يَدْخُلَ مَا رَأَى فَهَتَكَتِ السِّتْرَ وَفَكَّكَتِ الْقُلْبَيْنِ عَنِ الصَّبِيَّيْنِ وَقَطَعَتْهُ بَيْنَهُمَا فَانْطَلَقَا إِلَى رَسُولِ اللَّهِ ﷺ وَهُمَا يَبْكِيَانِ فَأَخَذَهُ مِنْهُمَا وَقَالَ يَا ثَوْبَانُ اذْهَبْ بِهَذَا إِلَى آلِ فُلاَنٍ أَهْلِ بَيْتٍ بِالْمَدِينَةِ إِنَّ هَؤُلاَءِ أَهْلُ بَيْتِي أَكْرَهُ أَنْ يَأْكُلُوا طَيِّبَاتِهِمْ فِي حَيَاتِهِمُ الدُّنْيَا يَا ثَوْبَانُ اشْتَرِ لِفَاطِمَةَ قِلاَدَةً مِنْ عَصَبٍ وَسِوَارَيْنِ مِنْ عَاجٍ