My position on the matter is made obvious by the fact that E had slowly-fading pink hair for about five months last year (we were amazed that it lasted so long), and M currently sports a subtle shade of purple. Our biggest problem is how to get color to show on M's dark brown locks. This is a problem because I refuse to let her bleach it (I do, occasionally, draw lines), but I'm sure that by high school, if not eighth grade, she'll be doing it herself.
This NY Times article on the subject typically confuses the issues: there is coloring hair, there is paying lots of money to color hair at a salon, there is the sociocultural landscape of hair color (which they barely touch upon).
We color hair pink and purple (next up: blue) at home on the cheap because my kids want to be punk/hip/pretty/different, which is a spot on the cultural landscape that they can inhabit but I certainly couldn't. But am I really any different from the moms who take their daughters to Frederic Fekkai for $400 caramel highlights because the girls want it and it will make them feel good about themselves? I like to think I am--in my DIY/boho self-righteousness--but maybe not.