Ruling on Women Using a Mixture to Smooth and Dye Hair

The honorable Shaykh: Abdul Aziz ibn Baz (may Allah preserve him). Peace, mercy, and blessings of Allah be upon you. After that: Some women use a mixture to smooth their hair. This mixture is composed of henna and a group of herbs. Among these herbs is one that dyes the hair black. What is the ruling on using this mixture? Knowing that they use it for the purpose of smoothing the hair, not for dyeing it black, since some of them have black hair. What is the ruling on its use by a woman whose hair is black, but there are white strands among it that have grown not due to old age? She also uses it for the purpose of smoothing her hair? Please inform us of this, may Allah reward you. And may Allah reward you with the best reward. From: A. Q.
A: And upon you be peace, mercy, and the blessings of Allah. After that: There is no blame on using the aforementioned paste to smooth the hair if the woman using it does not have gray hair. However, with gray hair, it is not permissible to use what makes the gray hair black; due to the saying of the Prophet (peace and blessings be upon him): .
May Allah guide everyone. And peace be upon you and the mercy of Allah and His blessings.