The prominent Muslim scholar and da`I, Zienab Mostafa states: “When Almighty Allah revealed the verse of hijab in Surat An-Nur, He set the requirements of the Islamic dress code for us. A woman has to cover her body. There is no precise description given, which means that she can cover herself in whatever way she wants as long as she covers her entire body except for the face and hands.
The matter of the dress code in Islam is flexible in order to accommodate people in every time, and every culture, and there is no certain design for the outfit, and no colour recommended or prohibited. So you can choose whichever colour you want as long as you follow the command of Allah.
The wives of the Prophet (peace and blessings be upon him), used to wear a black cloak because this was the custom at that time and it was obligatory for them to cover their faces as well. However, this does not apply to all Muslim women. Allah asked Muslim women to follow the wives of the Prophet (peace and blessings be upon him) in terms of behaviour and acts of worship. It is important for us to follow them in those ways. Some women follow them in their way of dressing, and I ask Allah to accept this from them, but it is not obligatory to follow their way of dress especially if you live in a western environment.”