She dyed her hair black without knowing that it is haraam. Should she leave it or change it?
Question

                I have a friend who dyed her hair black without knowing that it is haraam, and after finding out that it is haraam, she asked me whether she should re-dye it another colour or leave it as it is? And is removing the hair between the eyebrows haraam?.
Praise be to Allah.
    Firstly: 

    If there are any grey hairs, then dyeing them black is 
    haraam, but if the hair is already black, there is nothing wrong with dyeing 
    it black. 

    Shaykh Ibn Baaz (may Allaah have mercy on him) was asked: 
    Some women use a mixture to condition their hair. This mixture includes 
    henna and other herbs, one of which dyes the hair black. What is the ruling 
    on using this mixture? Please note that they use it for the purpose of 
    conditioning their hair, not for the purpose of dyeing it black, because the 
    hair of some of them is black. 

    He replied: 

    There is nothing wrong with using the mixture mentioned to 
    condition the hair if the woman who is using it does not have any grey 
    hairs. But if there are any grey hairs, it is haraam to use anything that 
    will make the grey hairs black, because the Prophet  (peace and 
    blessings of Allaah be upon him) said: “Change this grey hair, but avoid 
    black.” End quote.

    See also the answers to questions no. 
    476, 
    47652 and 
    1187. 

    Whoever does that – whether male or female – knowingly and 
    deliberately, has fallen into sin and has to repent, seek forgiveness, 
    regret what has been done and resolve not to do it again. Part of repenting 
    completely is removing the black with something that will not cause any 
    harm. 

    But if a person was unaware of the ruling, there is no sin on 
    him, but he has to change it. He is excused for it but there is no excuse 
    for leaving it as it is. 

    An example of that is tattooing. If a person was tattooed 
    when he was young, or when he did not know that it is haraam, then he must 
    remove it when he comes to know that it is haraam, so long as removing it 
    will not cause him any harm. 

    Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allaah have 
    mercy on him) was asked: 

    What is the ruling on tattooing? If a girl was given a tattoo 
    when she was young, is there any sin on her? 

    He replied: 

    Tattooing is haraam, and is a major sin, because the Prophet 
     (peace and blessings of Allaah be upon him) said: “The woman who does 
    tattoos and the woman who has a tattoo done are cursed.” If a girl is given 
    a tattoo when she is young, and she cannot prevent that being done to her, 
    then there is no sin on her, rather the sin is on the one who did that to 
    her, because Allaah does not burden any soul beyond its scope, and this girl 
    had no control over the situation. But she should remove it if she is able 
    to without that causing her any harm. End quote. 

    As’ilah tuhimm al-Mar’at al-Muslimah 
    (question no. 20) 

    Secondly: 
With regard to the 
    ruling on removing the hair that is between the eyebrows, in the answer to 
    question no. 21400 we have quoted the scholars of the Standing Committee as 
    stating that it is not part of the eyebrows, and based on that it is 
    permissible to remove it.

     And Allaah knows best.