I've seen more clips of Scandanavian people since Youtube came on the Internet...?

I've seen more clips of Scandanavian people since Youtube came on the Internet and noticed that some of them are dark as in having brown hair and brown eyes. When I was growing up, I was always lead to believe that Scandanavian people where all blond haired blue eyed people, but have found this not to be true. Are some people who live in the Nordic countries a mixture of different nationalities hence the reason I see some people who have dark hair and eyes? I was just curious about this because I'm an American of part Danish descent and I have brown hair and eyes, but I'm also part German. But I was wondering why some Scandanavians who actually were born and raised in the Nordic countries have dark hair and eyes.