Yup. I was a medium sandy blonde as a child. I still had blondish streaks in my hair as I approached my early teens, though my hair was more of a chestnut brown, no longer blonde except towards the ends. Then it turned medium mousy brown by my mid-teens and stayed like that. It's funny how it picks up reddish and brassy tones when I dye it, my roots otherwise look a dull dark brown with some grey streaks coming in. I wonder if climates somehow affect hair color, my cat's fur also got darker when we moved around to colder climates and then stayed dark, even when we moved back into warm climates. I guess it could have been a coincidence, but it happened with my sister too. Her hair was a reddish shade of brown and when we moved to a colder climate, it was a very dark brown, almost black.