Question: Oh virtuous Shaikh, may Allah preserve you*, is it allowed for a woman to wear a white or green hijab or other than it from the colors if it is from the custom of the people. Specifically, if it is argued by some that she must wear a Black Jilbaab?
Answer: There is no harm, if this is the custom of the people of the land, that she wear white clothing. However, it should not be the clothing of men. The color has no consideration however with the condition: that it distinguishes from the clothing of men. As for if it [the white hijab] is not from the custom of the people, then it is obligatory to follow the custom of the people of the land. She wears Black clothes, green clothes, red clothes, in accordance to the custom and she covers her entire face.
[Taken from al-Liqaa ash-Shahri no, 66 found here: https://shamela.ws/browse.php/book-7686#page-1914 ]
* May Allah have mercy upon him
Faisal ibn Abdul Qaadir ibn Hassan