A good color means natural. Look carefully at a fistful of hair in the mirror. See how each strand has a different tone? Perhaps even different colors on one strand? These are the natural striations that Mother Nature gives each head of hair to work with natural lighting. A good "color job" must duplicate these natural highlights to be effective.
Have you carefully factored skin tone and eye color into your decision? You really should you know. Nothing worse than walking around looking all washed because you picked the wrong color.