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The Science Behind Hair Coloring: Understanding the Process

Hair coloring is a popular beauty treatment that has been used for centuries to change the color of hair. Whether it's to cover gray hairs or to experiment with a new look, hair coloring has become a staple in the beauty industry. But have you ever wondered how hair coloring actually works? In this article, we'll dive into the science behind hair coloring to help you better understand the process.

The Basics of Hair Structure

Before we can understand how hair coloring works, we first need to understand the basics of hair structure. Hair is made up of three layers: the cuticle, cortex, and medulla. The cuticle is the outermost layer, which protects the hair from damage. The cortex is the middle layer, which gives hair its strength and elasticity. The medulla is the innermost layer, which is only present in some types of hair.

Hair color is determined by the amount and type of pigment present in the cortex. There are two types of pigment that contribute to hair color: eumelanin, which is responsible for brown and black hair, and pheomelanin, which is responsible for red and blonde hair.

How Hair Coloring Works

Hair coloring involves the use of chemicals to alter the natural color of hair. The most common type of hair coloring is permanent hair color, which involves the use of oxidative dyes to penetrate the cuticle and cortex of the hair. The dye molecules react with the natural pigment in the hair to produce a new color.

The process begins with the application of a mixture of dye and developer. The developer contains hydrogen peroxide, which helps to open the cuticle and allow the dye molecules to penetrate the cortex. Once the dye molecules have entered the cortex, they react with the natural pigment to produce a new color. The longer the dye is left on the hair, the more color will be deposited.

Semi-permanent hair color works in a similar way, but without the use of developer. The dye molecules are larger and do not penetrate the cortex as deeply, resulting in a less permanent color change.

Understanding Hair Color Levels

Hair color is often described using a numbering system that ranges from 1 (black) to 10 (lightest blonde). This system is used to describe both natural and artificial hair color. The level of color is determined by the amount of pigment present in the hair.

Hair color can also be described in terms of its tone, which refers to the underlying color that is present in the hair. For example, a level 6 brown hair color might have a warm or cool tone, depending on the amount of red or ash pigment present.

The Science of Color Correction

Color correction is the process of fixing hair color that has gone wrong. This can include correcting brassy tones, removing unwanted color, or fixing uneven color. Color correction can be a complicated process, as it often involves the use of multiple products and techniques to achieve the desired result.


Understanding the science behind hair coloring can help you make informed decisions about your hair and achieve the results you desire. By working with a professional stylist at Bolivar Salon, you can ensure that your hair coloring experience is safe, effective, and tailored to your unique needs. If you're looking to switch up your hair color or touch up your roots, book an appointment with Bolivar Salon today and let their experienced stylists help you achieve the hair of your dreams!

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