How does the sun make skin darker, but hair lighter?
he skin is a living organ which contains . The sun will destroy melanin, but being a living regenerative tissue. The sun destroys the melanin therefore your skin produces more, so a tan is a symptom of , it’s not an effort to protect your skin from further damage, it’s just a symptom of damage.
Hair will lose its color in the sun because even though it contains melanin it is made of of dead cells and cannot respond to the sun’s damage by producing more melanin.
The sun does not make your skin darker, your skin makes itself darker in response to the sun. Think of the dyes that make your skin and hair dark as a type of protective armor against ultraviolet rays. The dyes get damaged as they get bombarded by UV, and eventually turn lighter. But that’s the dyes getting damaged rather than your skin DNA getting damaged, so it’s doing its job. The difference between your skin and your hair is that your hair is dead and your skin is alive. So as you shine sun on your skin, your skin reacts by making lots of protective dyes, turning your skin darker. Your hair, on the other hand, is dead and can’t make any more protection than what it came with. So over time it gets lighter. If your skin stopped making dyes, it would get lighter too as the sun shines on it.