Grown-in roots may be a fashion statement for some, but most of us just want them to go away. If you've changed your natural color by more than about two shades, it's best to have a touch-up done at a salon -- correctly applying the color on your own is a tricky proposition, and you could wind up with an uneven mess. If the difference between your roots and ends is less noticeable, simply follow the directions for touch-ups that come with your color.