Ash-Shama'il Al-Muhammadiyah, Book 52, Hadith 367 (English) ⓘ

Anas Radiyallahu 'Anhu reports: "Rasulullah Sallallahu 'Alayhi Wasallam was not of a tall height nor was he short. (According to colour) he was not very white, nor very wheat coloured (dark). His mubaarak hair was not very curly nor very straight (but was slightly curled). He was blessed with prophethood at the age of forty, after that he lived for ten years in Makkah Mukarramah, and ten years in Madinah Munawwarah. At the age of sixty years Rasulullah Sallallahu 'Alayhi Wasallam passed away. At that time he did not have more than twenty white hair in his mubaarak head and beard".

حَدَّثَنَا إِسْحَاقُ بْنُ مُوسَى الأَنْصَارِيُّ، قَالَ‏:‏ حَدَّثَنَا مَعْنٌ، حَدَّثَنَا مَالِكُ بْنُ أَنَسٍ، عَنْ رَبِيعَةَ بْنِ أَبِي عَبْدِ الرَّحْمَنِ، عَنْ أَنَسِ بْنِ مَالِكٍ، أَنَّهُ سَمِعَهُ، يَقُولُ‏:‏ كَانَ رَسُولُ اللهِ صلى الله عليه وسلم، لَيْسَ بِالطَّوِيلِ الْبَائِنِ، وَلا بِالْقَصِيرِ، وَلا بِالأَبْيَضِ الأَمْهَقِ، وَلا بِالآدَمِ، وَلا بِالْجَعْدِ الْقَطَطِ، وَلا بِالسَّبْطِ، بَعَثَهُ اللَّهُ تَعَالَى عَلَى رَأْسِ أَرْبَعِينَ سَنَةً، فَأَقَامَ بِمَكَّةَ عَشْرَ سِنِينَ، وَبِالْمَدِينَةِ عَشْرَ سِنِينَ، وَتَوَفَّاهُ اللَّهُ عَلَى رَأْسِ سِتِّينَ سَنَةً، وَلَيْسَ فِي رَأْسِهِ وَلِحْيَتِهِ عِشْرُونَ شَعَرَةً بَيْضَاءَ‏.‏