Tanning lotion lol I think you asking about melanin darker you are the more melanin you have
Melanin is what gives skin its pigment. Some people have more of it than others, and sunlight activates it.
Melanin
Anumasu
Melanin
melanin
Melanin
melaninMelanin
Melanin
Keratin
Keratin
Keratin
Skin- melanin. Hair- keratin.