If you have opted for a professional hair dye color instead, do note that you will need to purchase the peroxide developer separately. Developers come in different strengths, from 10 Volume (also called 3%) to 40 Volume (12%) peroxide, with 10 Volume being the weakest developer. The strength you should choose depends on two factors, namely the condition of your hair and the desired hair color you want to achieve.
Let's talk about the condition of your hair first. Common sense would tell you that if your hair is already damaged or overly processed from other chemical treatments such as relaxers and perms, then you choose definitely choose a lower strength peroxide developer so as to not further weaken your hair. A 10 or 20 Volume developer would be a safe bet in this case.
For more info:
side effects of applying vicks on hair
