The hair on my head is a coppery red. Exposure to the sun bleaches it lighter. The hair on my arms is usually a pale blond shade- except in the summer. In the summer, once I’ve been out doors enough for my freckles to darken (but not my skin in general since I don’t tan) the hair on my arms darkens to a orange-red shade; I don’t have a sun burn so I don’t think it’s getting red from reflecting off my skin or anything along those lines. However, this is only where it has been exposed to a lot of sun, because the hair on my inner arms and upper arms (I never where sleeveless shirts) is still that blond color…my eyebrows are still blond as well.
So why does the sun lighten some of my hair and darken the rest?