Is it permissible to dye hair black if the hair's original color is black?

The Prophet Muhammad (peace be upon him) forbade dyeing hair black. He commanded changing gray hair but avoiding black. Some scholars explained this prohibition as being due to deception, fraud, and presenting oneself as other than one's true self.

As for hair that has no grayness but has turned red, it is better and more cautious to avoid dyeing it black, in deference to the wording of the hadith.

A Muslim woman should not waste her time on adornment. Rather, she should focus on her worship and raising her children, and adorn herself moderately with what Allah has permitted, and not follow every new fashion, to avoid imitating disbelieving and immoral women.