The good news? It's TOTALLY normal! Actually, there are a few reasons to explain this observation.
For one, premature grey hair is genetic. More than likely, it runs in the family to have grey hair at a young age, just like premature baldness is genetic as well.
Another reason to explain the observation is if you die your hair. Getting your hair color changed at a salon doesn't harm your hair even the slightest, but if you die your hair via boxed die, you will eventually begin to grow grey hair. Which seems like an unlikely explination for you, because not many males die their hair.
Another explination would be your shampoo. Some shampoos actually DAMAGE the hair to the extent that your hair will resort to losing it's color, hense the new grey tone.
There are several reasons for why this could be happening, but know that it's totally normal.
No not at all. My friend Nabil who has black hair had some grey hairs when he was 17. It's just the pigment in your hair fading no biggie you won't be going grey any time soon, but a few grey hairs at this age isn't unnatural.
Well it's uncommon but not abnormal. It depends of your genetic. When my mother was 18 she knew a guy that already has grey and white hair...I mean ALL grey. And a friend of mine (who's 16) have some white hair... I don't think you can do anything about it though.
It isn't hugely common but it's not unusual either. I've heard of lots of people around our age with grey hairs.
I'm fifteen and my friends have started to make a habit of pulling out my gray hairs in Gym class everyday. It's not that they're extremely noticeable (at least, I hope not) but my friends are weird/bored :)
My cousin found his first gray hair at the age of seven
My friend has a boyfriend who is 18 and has pretty noticeable grays.
Sometimes, it's a vitamin deficiency. You can ask your doctor about this, if you think that's the case. A lot of times, its genetics. Lucky us, right?
It's normal. I have a handful of gray hairs myself, probably stress related but possibly genetic. My uncle was fully gray by 25. I wouldn't be too concerned about it, since it's going to be what it's going to be.
It is uncommon but not unheard of. Some people just start to go gray early. For some reason this seems most common among people with dark hair. I would bet that either your father or mother also went gray early.