As a colorist at the Oscar Blandi salon for over 15 years, I consider certain things when a client (new or regular) comes in wanting to change her hair color. Although there aren't any hard rules — ultimately, you should go with the color you want — the tricky part is a lot of women don't know what that is when they walk in.
Some women come into the salon without a picture or any descriptors; the only thing they know is they want to get their hair colored. Oftentimes I hear, "I want to go blonde," but even that leaves the decision-making process to me. You may say "brown," but what I hear is something quite different — and it's up to me to use my skills and knowledge in choosing the right shades and make them work for your particular head of hair.
Fortunately, I have some key considerations to help me choose colors for the diverse range of women who sit in my chair: skin tone, time of year, a person's lifestyle, and even the mood a particular color can evoke. I've been doing this for so long that it typically doesn't take me long to assess a woman's features and coloring, ask her a few questions about herself, and get her talking about her expectations before I figure out what color will look incredible on her.