This more a comment on the new color line -- which seems to have a steep learning curve, and is more complicated than the old one.
I get a lot of shade variation from visit to visit, and my formula is still up in the air. For example, at one visit the shade will be right, but at the next visit it will be a shade lighter, although supposedly the exact same formula was used!!? What's up with that?
If the new color line is too complicated for busy stylists to record down, or if they need better access to computers in which to record formulas, or if they need more basic training in the new line, please address it. I have had numerous "oops" experiences since it was introduced.