Some scholars say that using black hair dye and praying is not valid. Is it true? SALAAM.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

The scholars differed in opinion about the ruling of dyeing hair black, some of them are of the view that it is forbidden, and some of them are of the opinion that it is dislike, while some others hold the opinion that it is permissible.

However, as far as we know, no scholar has ever said that the prayer of a person who dyed his hair black is void. There is no relation between dyeing the hair in black and the validity of the prayer. For more benefit, please refer to Fatwa 92351.

Allaah Knows best.