Why does our skin change colors if we're in the sun for a certain amount of time?

Question

well obviously, but like, scientifically

Answer 1

The deepest layer of skin contains melanin, the same chemical responsible for the color of your hair.  When you've been out in the sun, it activates this melanin, causing it to darken.  The reason it darkens is to reflect sunlight and protect the skin burning.  That's what causes you to get a suntan.

Answer 2

uv rays

Answer 3

idk...................