Well if damage is what you're worried about, then you should try a henna treatment then follow it up with and immediate indigo treatment to achieve a very rich black. Most people aren't aware of the range of color they can get using henna. The shine and the volume benefits are definitely a plus and you don't have to worry about it destroying your hair. I've been using henna for 4 months and am seeing excellent results. Check out these sites for info.

Curlynikki.com
hennaforhair.com