Q: Why is the temperature important when coloring hair? Some salons use artificial heat when others just rely on head heat, is
it something to do with the condition of the hair?
A: Usually, the application of heat to the head when performing a color service is to help speed the lightening of the hair by the
developer in the color mixture. Heat will speed up the “lifting action” of the color mix, ensuring that the color lightens evenly all
over. This applies even if you’re going from one color to a color only a few shades lighter, but of a different tint, for example:
from a light brown to a dark strawberry blonde. For the hair color to turn out correctly, you want to make sure that the hair is
sufficiently lightened for the color to deposit and give the desired results ...
Whether or not the colorist uses heat to help with the processing may also depend on the strength
of the developer used and the desired color. Sometimes, when the colorist is only performing a retouch to previously colored hair, he
or she will not use heat when he or she may have done so previously to prevent further lightening of the already colored hair. The
heat of the scalp will have made sure that the new growth lightened sufficiently to match the rest of the hair.
Heat may also be used on the hair when coloring if the hair has proven to be resistant to
haircolor in the past. This may be the case when dealing with gray hair or other hair that is typically resistant to chemical processing.