Why is this Bohemian? Because it's living outside the norm; it's unique, interesting & artistic.
Obviously, what we do with our hair affects our overall appearance. It shouldn't matter to others how we want to express ourselves. However, there definitely is social stigma still attached to unique hair coloring. I think that's a shame. The world would be a far more interesting place if everyone had the confidence and creativity to display themselves colorfully. Props to those to who live life bold!
For those who desire a color change, but not ready for dye, think about a wig or hair extensions at etsy.