The Ruling on Dyeing the Hair
Answered by Shaykh ʿAbd al-ʿAzīz ibn Bāz
The Question
Her third question: Is dyeing the hair lawful (ḥalāl) or forbidden (ḥarām)?
The Answer
Dyeing the hair, if it is with pure black, is not permitted for men and women alike. But if it is dyed yellow, or green, or something other than that, there is no harm in it. As for pure black, the Prophet ﷺ forbade it. He said:
غَيِّرُوا هَذَا الشَّيْبَ وَجَنِّبُوهُ السَّوَادَ
“Change this grey hair, but avoid black.”
So the conclusion is that it is not permitted with pure black, neither for the woman nor for the man. But if the grey is changed with something other than black, such as black mixed with henna, or with red, or with yellow, there is no harm in it. Yes.
Source: binbaz.org.sa (Nūr ʿalā al-Darb).