I always do it myself. I agree, color doesn't always come out the way that you want it, but then you just do it over again. That's what I did. I also went from very blonde (I've been a blonde for about 15 years) to dark ash blonde and the hair came out with a shade of blue to it. So I went and got another color a little darker then before and it came out right.
I've been coloring my hair for over 15 years and I have always done it by myself and the color looks great.
I actually have a friend who's a stylist, gets her hair done at her own salon and her hair looks way too bleached out and damaged.