by Marlin Bressi

Created on: March 31, 2009

When coloring hair a bright and vibrant shade, it is often necessary to pre-lighten the hair using bleach. If a haircolor is applied to brown hair, for instance, the results will be far less visible. It is much like painting a wall: If your desired color is blue, you will have to strip off the old paint and primer the wall before painting it blue. The same is true with hair. Applying blue hair dye to hair that is already brown is much like trying to paint a brown wall blue. The results will not be very impressive.

Certain colors will require more pre-lightening than others. Red, for instance, can be applied to hair that has been lightened slightly, since bleaching the hair for a short period of time will bring out orange and yellow tones in the hair, making it a perfect "canvas" for which to apply red dye. The same is true for other warm colors, such as orange or yellow.

Other colors, such as green and blue, require more pre-lightening. When dyeing hair green, it is best to lighten the hair to a pale yellow shade before applying the green color. Since green is a mixture of blue and yellow pigments, it is important to remove any naturally-occurring red pigments in the hair. Red pigment occurs naturally in all shades of brown hair and red hair. If there is any residual red tones in the hair, applying green will create a muddy brown tone instead of a bright and vibrant green.

Blue is perhaps the hardest color to achieve because it requires the most pre-lightening. Hair must be bleached out of the yellow stage before blue is applied, otherwise the residual yellow pigments in the hair will create a blue-green color rather than a true blue. Since yellow is the smallest-sized pigment found in the hair, it is the hardest color to remove.

In order to understand the importance of pre-lightening the hair, it is important to understand the stages of lightening that occur when hair is bleached. Before hair is lightened to the platinum stage, it must pass through the red stage, then red-orange, then finally yellow. Since the molecular size of a red pigment is much larger than a yellow pigment, it doesn't take long to bleach the hair from brown to red-orange, but it takes much longer to bleach the hair from red to platinum.

As you can see, the final result depends not only on the shade of haircolor being applied, but also on the hair's color prior to applying the dye. This is why it is always best to bleach the hair before attempting to go a shocking, bold, and vibrant color.

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