Probably because you're pale and have light colored hair too..?
Hmm.. Well yeah I'm pretty pale. But the "light" colour comes just from the light. And also from that, when I had short hair, I mean very short, I had taken some light streaks on it. And now when I wear ponytail it looks like that, that I have a light coloured hair, just because you can see most parts of the hair where the streaks were added.