Different Hair Colors
Monday, 22 April 2013
Thursday, 4 April 2013
Different Hair Colors and why they are different
Different Hair Colors and why they are different
Do you know why web hair have different hair colors? Why is hair comes with four colors, blond, brown, red or black? The ultimate answer, of course, is that hair color is genetically determined, the same as skin color. If your parents and earlier ancestors had black skin and black hair, the odds are that you will also have black skin and black hair. Or, if your parents and ancestors had white skin and blond hair, it is very likely that you will also have white skin and blond hair-unless, perhaps, some ancestors with different color skin and hair slipped into your ancestry at some time in the past.
Having said that, the follow-up question is: Why do humans have different skin and different hair colors? Why don't we all have skin and hair of the same color? The best evidence available to science indicates that humans originated in Africa and migrated from there into the rest of the world over a period of several million years. The only human remains from those millions of years are bones; however, it is hypothesized that these early humans had brown or black skin, since that is the heritage indicated by people living in Africa today. White skin and blond or red hair appears to be a mutational development that occurred within approximately the past 50,000 years, probably in or near Europe. Why did this happen? There is no certain answer to that question yet. However, geneticists who trace human genes throughout human history point out that skin and hair color are traits that are highly likely to respond to the evolutionary pressure of climate. Thus, light-colored skin that synthesizes vitamin D more readily than dark skin in response to sunlight could have conferred a survival advantage in northern climates, where sunlight is weak, as humans moved north along the edge of the retreating glaciers of the Ice Age.1
different hair colors |
Different types of hair colors:
Several hair dye colors have been used for coloring the hair depending
on the personal taste and features of people. When it comes to different hair colors, there are two types of hair colors namely permanent and temporary hair
color. Temporary colors won’t ammonia and hydrogen peroxide. This type of
colors will coat the cuticle and after one shampoo the color will fade. The semi
permanent colors have been used on people with gray hairs. Such colors blend
with our hair and they will start fading after a few weeks. Demi permanent
colors come with low peroxide and they are for people with gray hair and these
colors normally fade after 2 months. Permanent colors come with both peroxide
and ammonia and these colors need to be applied once in four or six weeks.
How Hair Gets Its Color
The color (pigmentation) of hair is put there by melanocytes,
specialized cells that synthesize the pigment melanin. The melanocytes that
synthesize melanin for hair are located in the hair follicle. Melanocytes are
also distributed throughout the body-in the eyes, the ears, the central nervous
system, mucous membranes and skin. Differences in skin color are largely determined by the reddish-brown
to black melanin pigment synthesized by melanocytes in the skin. Differences in
eye color are determined by melanocytes located in the eye. Other pigments
contributing to skin color or carotenoids (yellow), oxygenated hemoglobin (red)
and reduced hemoglobin (blue).
Melanocytes in the hair follicle are active only during the anagen
(growth) phase of the hair cycle (see How and Why Hair Grows). No melanin is
synthesized during the catagen (degradation) or telogen (resting) phases of the
hair cycle. Two major types of melanin are synthesized by melanocytes that are
specialized to synthesize just one type of melanin, Eumelanin, a brown/black pigment that gives the color to brown and
black hair, is synthesized by oval-shaped melanocytes and, Pheomelanin, a yellowish to reddish-brown pigment that gives color to
red and blond hair, is synthesized by spherical melanocytes.2,3.
Changing Hair Color, Minimizing Damage
Hair color is one of those highly visible characteristics that
individualizes a person. That's a frequent reason for wanting to change hair
color or reinforce and brighten the color that naturally exists. Change of hair color may lend a characteristic prized because it has
charismatic socio-cultural power. It may make a fashion statement. Or, change
of hair color may just be a way to put a little excitement in one's life.
For all of those reasons and more, millions of people change hair colors every year, using home hair-coloring kits or using the services of a hair-care
professional in a salon.
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