Most Helpful Guy
Depends if you can rock it or not lol.
Most Helpful Girl
I think that teens can easily get away with it, considering that that's when most people do stuff like this. I mean, I dyed my hair bright red when I was 16/17. So I think it's fine, as long as you take care of your hair well and make sure you put effort into maintaining the color (nobody thinks that faded dyed hair + crazy long roots + massive split ends look good). If you feel like you'd be too lazy to maintain the color by dying it at least once a month, then a bright color is probably not for you. Bright colors look the best when they're bright and freshly dyed. Not when they have faded and your roots are showing. So, it's quite the task to maintain it. I guess that's why dip dyes are a bit more popular, since you don't have to commit as much.
Anyway, yeah, as long as you put effort into it, I think brightly dyed hair can look really cool. If you want to do it, then go for it.