Hi there, looking for some advice please! I recently got my hair dyed a royal blue at my local salon and I am in love with the color! But I'm starting to think ahead to when my roots grow out and how to deal with this. As a student I really can't afford to be visiting the salon every time my roots start to show, can anyone offer suggestions of good "permanent" blue at home dyes that I can use to touch up my roots when the time comes?