Once she studies your hair, its condition, its style, its cut, and your lifestyle (e. g., how much time you plan on spending on your hair each day), she will then make some recommendations for color and maybe even a more suitable style for you. Plan on being there for a few hours.
Hard as it is to believe there was once a time when those who colored their hair were looked down on by "respectable" women. Some would sneer, "She gets her color out of bottle, you know." Making it sound like that was a bad thing.