A hairy dilemma

I have a dilemma. I may be The Green Grandma, but that doesn't mean I want to be The Grey Grandma! I don't want grey hair. Period. But this hair dying routine I go through every six weeks or so has me feeling a little bit guilty. After all, the toxins and heavy metals I'm putting onto my head and then washing down the drain cannot be doing me or the earth any good, and chances are, they're doing both of us a bit of harm.

As a matter of fact, research shows that home-dye solutions can contain quite a few known carcinogens, including Acid Orange 24, 2,3-Naphthalenediol and F,D,&C, D&C, and P-phenylenediamine.  So what do I do?