Any skin colour is suitable for permanent makeup brows!
I have a range of different coloured pigments to suit different skin and hair colours. So if you have fair skin and blonde hair I will use lighter coloured pigment, and if your skin is dark I will pick up the darkest brown pigment to match your complexion.
Pure black pigment should never be used for brows as it will look bluish through the layer of the skin! Very dark brown colour is used to get darker coloured brows.