To fix bad hair highlights, a person must go see a professional hair colorist and get lowlights put into the hair. Lowlights are the best way to combat bad hair highlights because they work to create a more natural look while removing the stark contrast that can be seen with bad highlights that are streaky or chunky.
Lowlights are similar to highlights in that they are both partial coloring techniques; however, lowlights are used by colorists in order to add dimension and to break up the color in the hair. Lowlights are always lighter than an individual's natural hair color, but are darker than the highlighted color used on the same individual's hair color.
An example of a person with highlights and lowlights can be illustrated by a person with dirty blonde hair. This person would get light golden blonde highlights and would get light cool brown lowlights. The important part is to not go more than two shades darker or lighter than the individual's natural hair color if the individual wants a beautiful natural look.
Colorists add deep lowlights to hair by painting the lowlights on to the hair starting at the scalp. They then go down to the mid-strand. It is crucial that they do not place the lowlights throughout the full hair strand or the results will not be a natural look.