Incredible What Does It Mean When Your Hair Changes Color References. With enough direct sunlight, you may start to notice a significant difference between the color of the top layers of your hair and the underside. What is the most beautiful hair type?

Sunlight ultraviolet light breaks down melanin through repeated and extended exposure. This will result in the top layers of hair that are most frequently exposed to sunlight bleaching over time. This happens because the sun’s ultraviolet (uv) rays alter your hair’s melanin levels, which determine how dark or light it appears naturally.