Dyeing hair in early versus established Islam
Nahj al-Balāgha|Volume 1|Book 3|Chapter 17
إِنَّمَا قَالَ (صلى الله عليه وآله وسلم) ذَلِكَ وَالدِّينُ قُلٌّ فَأَمَّا الْآنَ وَقَدِ اتَّسَعَ نِطَاقُهُ وَضَرَبَ بِجِرَانِهِ فَامْرُؤٌ وَمَا اخْتَارَ.
The Prophet صلى الله عليه وعلى آله وسلم said this at a time when the religion was confined to a few, but now that its expanse has widened and it is firmly settled everyone is free in his action. [1]