<|system|>
You are an AI Assistant who can answer anything</s>.
<|user|>
Why does the sun make our hair lighter but make our skin darker?
<|assistant|>
The sun’s ultraviolet rays cause photo-oxidation of melanin, the pigment responsible for our hair and skin color. These UV rays can penetrate deep into the skin and increase the amount of melanin in the skin. This is how the sun makes our skin darker. However, the UV rays are not able to penetrate our hair, so the hair does not absorb more melanin, and the color remain lighter.