I grew up in a beach town, San Diego. As a kid, I was in the ocean more than most fish. I loved to play on the beach, get dirty in the sand, and catch a wave on my "boogie board." Mom always made sure we had sunscreen on, but I still had a tan most of the year, and my hair was blonde...VERY blonde.
But if my skin was getting darker, how come my hair was getting lighter? Turns out skin and hair react differently to sunlight.
I asked my doctor that question a few years ago. Also looked around on sites like Livestrong.com, and they summed it up like this:
"Typically, the skin darkens and the hair lightens, a result of a pigment in the human body called melanin. Melanin darkens the skin to protect it from harmful solar radiation. Because hair cells are not alive like skin cells are, melanin cannot protect hair from sun damage. Hair takes on a bleached appearance, while skin becomes darker."
So, the best advice my doctor told me was "Don't stay out longer than 15 minutes or you start to damage your skin." Problem is, we never listen to our doctor, and end up looking like the picture above, with a bad sunburn.
Remember, we all need some sunlight, and some of the sun's rays are actually beneficial. But like anything in life, too much is never a good thing.