Why are there multiple hair colors in my brush?

I took the hair out of by brush and noticed that there is brown hair in it too, but mine is blonde and doesn't turn in the summer either. I'm the only one who uses it besides my brother sometimes, but he has short, even lighter, blonde hair. I was wondering why the brown hair may be there? Does anyone know?Why are there multiple hair colors in my brush?
maybe a friend used it or dirt went on it after a while so it turned brown. or maybe its dead hair so it go tdarker.Why are there multiple hair colors in my brush?
Maybe someone else in the house with darker hair picked up your brush and used it when you didn't know about it?





I'm not sure really. I don't think your hair could just turn after it sat in your brush a while.