Why does sunlight darken skin but lighten the colour of other surfaces?

Question

Why does sunlight darken skin but lighten the colour of other surfaces?

In: 30

Answer 1

Your body creates a protective layer in response to UV radiation damage. This layer is made from melanin, and it is darker-colored.

The same radiation damage that gives you a sunburn will also damage inanimate objects, too. They are not alive and cannot try to protect themselves, so some molecules within that object simply get destroyed. This often includes the molecules that make something have a color.