Highlights are a hair coloring technique where sections of the hair are lightened to add contrast and dimension to the hair. The technique can be done using foils, a cap, or by hand (such as with balayage). The hair is typically lightened by one or two shades, but can be lightened to be much lighter. Highlights can be done in a variety of colors, such as blonde, red, and caramel. They are a popular way to add depth and interest to hair and can be done on any hair type or length. It can be used to add some brightness or to add some color to the hair.