I have blue hair, your argument is invalid
Just did this on Monday:
A bottle and a half of Special Effects Electric Blue over unbleached blond hair.
I've been wanting to dye my hair outrageous unnatural colors for years now, and somehow didn't get around to it until now. I think a part of it was fear of destroying my hair with bleach (which I now realize isn't necessary for my hair) or of needing to get a real people job that would forbid magical hair (which my business is successful enough that I'm pretty sure I'm never going to have to do).
If you've ever considered dying your hair, I highly recommend it. This is one of the most spiritually satisfying things I've ever done. Not quite as spiritually satisfying as whooping ass in my last MMA fight, but far beyond anything a church or religion has ever offered.