The Prophet ﷺ said, "Jews and Christians do not dye their hair so you should do the opposite of what they do.  

قَالَ النَّبِيُّ ﷺ إِنَّ الْيَهُودَ وَالنَّصَارَى لاَ يَصْبُغُونَ فَخَالِفُوهُمْ