Hair Coloring and pH LevelQ: Why is it important to restore the pH level of hair after coloring?
A: When you color your hair you are causing the hair cuticle to swell or open up. This happens so that the hair dye can enter into the hair shaft. During the hair coloring process you are also causing the pH level to rise.
Hair's natural pH level is between 4.5 and 5.5 so when it is raised you are opening the hair cuticle. It's important to restore the pH level of hair so that it closes again and therefore keeps your hair color locked in.
How to color hair
Hair color and pH level
The natural pH level of hair