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How
do we get all these different hair colors and shades
If you have read the pages Hair color
- what is it and Hair color - biochemistry,
you will have a good idea as to how we get so many different shades
and colors of hair. Basically, the natural color of the hair is
decided by, what type of melanin is in the hair, how much melanin
is in the hair, and how densely packed the melanin is within the
hair fiber.
So black hair is the result of a very high production of eumelanin
which is very densely packed into the hair fiber. Brown hair comes
in various shades and richness of color but basically brown haired
people have a somewhat lower density of eumelanin in their hair
fiber. The warmer, richer tones of brown hair are due to a greater
presence of red - yellow pheomelanin. So the relative quantities
of eumelanin versus pheomelanin in brown hair increase the heterogeneity
of brown colored hair. Blonde haired people have eumelanin in their
hair fiber as for black haired people, but the eumelanin is present
at a very low density. Plain blonde hair is predominantly eumelanin
while richer honey blonde hair has relatively more of the yellow
red pheomelanin present. Red haired people have a high density of
the pheomelanin pigments in their hair fiber. Those who produce
virtually no eumelanin have a red to orange color depending on the
density of the pigment in the hair fiber. Red haired people who
have a greater relative proportion of eumelanin production have
a deeper red to red brown color. Gray hair is essentially the result
of reduced pigment production. The contrast between the hair with
more color and the hair with less color, causes the appearance we
call gray hair.
With so many different factors influencing hair color you might
also be able to perceive why each individual may have hair fiber
with different shades of the same basic color. Not all hair follicles
are created exactly equal. While in one hair follicle there may
be a little more eumelanin production or may pack a slightly higher
density of melanin into the hair fiber, the hair follicle next door
may not be quite so efficient. So when looking at individual hair
fiber colors everyone sees some slight differences in the shade.
So long as this variation is evenly distributed across the scalp
we perceive one overall color when we look in the mirror. Only when
a distinct area of follicles start producing more or less pigment
do we identify that region as being a different color to the rest
of the scalp hair.
Overall then there are many different interactions that lead to
the subtle and not so subtle differences in hair color. Anthropologists
and forensic scientists are most interested in this area and try
to compare hair color between genetically distinct population to
find identifying traits that can be exploited in their respective
fields.
How
do we get all these different hair colors and shades references
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