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.
Plus few things offer the opportunity to change your look the way changing the shade of your tresses does. It lets you keep everything else virtually the same while still giving you the change you seek. Not a bad deal actually.