Haircolor Levels and Peroxide DeveloperIn any discussion of haircolor, it is important to talk about color level and developer. Level refers to the lightness or darkness of a particular haircolor. It's shown on a scale of one to ten with 1 being black and 10 being palest blonde. The haircolor formulas available also have a level on this same scale. This tells you how light or dark the finished color will be.
Developer is the oxidizing agent that allows the haircolor to do its job. Most permanent haircolor today uses hydrogen peroxide as a developer. The peroxide opens the cuticle so that the color can penetrate. It also disperses the existing color and can lighten the hair's color level depending on the strength of the peroxide formulation. The peroxide developer's oxidizing potential is denoted as its 'volume'. Most haircolor formulas today work with a 10, 20, or 30 volume developer. The effects of these developer strengths are as follows:
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10 Volume Peroxide is a standard oxidizing strength for permanent, no-lift haircolor. Designed for use when you simply want to add a tint or color tone to hair of the same lightness level, 10 Volume Peroxide opens the cuticle layer of the hair allowing the color molecules to penetrate and color to be deposited in the cortex.
20 Volume Peroxide is also a common strength with permanent haircolor and opens the hair cuticle like 10 Volume, but also offers lifting of the hair's level by 1-to-2 levels. 20 Volume Peroxide is used to best effect when the hairs starting level is no more than one shade darker than the color you are trying to achieve.
30 Volume Peroxide works just like 20 Volume except that it will lift the hair's starting color by 2-to-3 levels and works best when the target color is no more than two levels lighter than the starting color. It's important to remember that the stronger the developer is, the harsher it can be on your hair. You should always use a moisturizing conditioner after applying a stronger haircolor.
There are Hydrogen Peroxide Developers that are stronger than 30 Volume (there is also 40 Volume and 50 Volume formulas), but you should NEVER use these strengths on your own. Developers above 30 Volume strength work very quickly, and without careful monitoring, these formulas can destroy the integrity of your hair.
Right now, you're probably asking yourself "If 30 Volume Peroxide is the strongest developer you recommend, how do I get my dark brown hair (level 3) to blonde (level 8)?" The answer is relatively simple. You'll need to use a lightener first. Lighteners are bleaching agents that are mixed with developers to decolorize - or lift the color from - the hair, usually in preparation for adding a lighter color tone, or for generating dramatic highlights.