There are several options when it comes to coloring your hair, and your stylist has had extensive training on getting your hue "just right."
But you don't need to go through beauty school to understand how hair color works, or the different types of formulas that are available. Here's a basic idea of what your stylist is doing when he/she colors your hair.
There are three main types of hair color:
Permanent is as the name implies, and lasts until your hair grows out. It enters the hair shaft and replaces your natural color molecules.
Semi-permanent and demi-permanent hues wash out over time, usually after 25 to 30 shampoos.
Temporary color coats the outer hair shaft and washes out instantly.
A developer is used with both permanent and semi-permanent formulas. It contains hydrogen peroxide to open up the outer layer of the hair shaft, lift the color molecules out, and deposit the new color into your hair.
When you want to go much lighter, your stylist may decide to use bleach, then apply additional color to give your strands just the right tint. Bleach should only be used by a stylist, as it can damage your hair if you leave it on too long. If you hair is naturally very dark, you will most likely have to head to the salon multiple times to obtain a pale or very light blonde.
Hair color is a fun and quick way to change up your look. It is one of the most requested salon services, so it is important to become an informed client. Next time you're in the chair, ask your stylist which formula she uses and why. She'll be happy to share her knowledge with you!