Question

how does our skin darken in the sun

Answer 1

I guess its just tanning.. the sun makes the skin darker..idk let me check it..

Answer 2

this is what i found hope it helps..
The skin contains a pigment called melanin that becomes destroyed when it is in contact with the sun's rays. The body counteracts this by producing more melanin and this pigment causes the skin to become darker. Hair on the other hand is 'dead' but it too contains melanin so when the sun destroys the melanin in your hair nothing replaces it with more melanin and it stays bleached.