FACTS:
Hair Color
Hair color is the result of pigmentation due to the presence of the chemicals of melanin and phaeomelanin. Human beings have many variations in hair color and hair texture. In general, the more melanin present, the darker the hair color; less melanin, the lighter the hair color. Usually the color of children's and adults' hair varies from pale yellow (blonde) to deep black. Hair may also come in more than one shade of color on one's head. As an example, the shade of one's hair color may change from a light shade to a darker one as time elapses. The ethnic distribution of colors has historically varied by geographic area. For example, black hair predominates outside of Europe, with the darkest shades occurring in East Asians. Black, brown, blonde and red hair occur in Europeans with the lighest shades occurring in Northern Europe . Considerable differences in hair color and texture exist between individuals of similar ethnicity, and immigration and global travel have greatly increased the diversity of hair characteristics in many countries. People also dye their hair to colors that do not occur naturally.Hair Coloring
Hair coloring products generally fall into four categories: temporary, semipermanent, deposit only/demi, and permanent. All these hair color products, except for temporary color, require a patch test before application to determine if the client is allergic to the product. "Hair lightening," referred to as "bleaching" or "decolorising," is a chemical process involving the diffusion of the natural color pigment or artificial color from the hair. This process is central to both permanent hair color and hair lighteners. All "permanent" haircolor products and lighteners contain both a developer, or oxidising agent, and an alkalizing ingredient as part of their ammonia or an ammonia substitute. The purpose of this is to: raise the cuticle of the hair fibre so the tint can penetrate, facilitate the formation of tints within the hair fibre, bring about the lightening action of peroxide. When the tint containing the alkalising ingredient is combined with the developer (usually hydrogen peroxide), the peroxide becomes alkaline and diffuses through the hair fibre, entering the cortex, where the melanin is located. The lightening occurs when the alkaline peroxide breaks up the melanin and replaces it with new color.Double Process Color
Consists of pre-lightening the hair first then toning it to the desired color. This method is also recommended prior to the application of vibrant fashion colors such as Ink-Works by Paul Mitchell.Temporary Hair Color
The pigment molecules in temporary hair color are large and, therefore, do not penetrate the cuticle layer, allowing only a coating action that may be removed by shampooing. Acid dyes are used to coat on the surface of hair, since acid dyes have a low affinity to hair, thus can be removed after a shampoo. Temporary hair color is available in various product forms including rinses, shampoos, gels, sprays, and others. This type of hair color is typically used to give brighter, more vibrant shades or colors such as orange or red, that may be difficult to achieve with semi-permanent and permanent hair color. This phenomenon is due to the fact that temporary hair colorants do not penetrate the hair shaft itself. Instead, these dyes remain adsorbed (closely adherent) to the follicle and can be easily removed with a single shampooing. However, even temporary hair coloring agents can persist if the user's hair is excessively dry or damaged, conditions that allow for migration of the dye from the exterior to the interior of the follicle. While temporary hair color products hold a lesser market than semi-permanent and permanent agents, they have value in that they can be easily and quickly removed without bleaching or application of a different dye.Semipermanent
Formulated to deposit color on the hair shaft without lightening it. This formula has smaller molecules than those of temporary tinting formulas, and is therefore able to penetrate the hair shaft. Has no developer, may be used with heat for penetration. It also lasts longer than temporary hair color, keeping intact up to 8-14 shampoos.Demipermanent
Uses a mild, creamy developer of a lower volume to other products of same or similar composition, including but not limited to the dye used in textiles, sunscreen, rubber, and/or certain medications. Henna is a deposit-only hair color whose active component, lawsone, binds to keratin and is therefore permanent. Henna may be removed with mineral oil; however, it is considered "permanent" because it does not wash out with shampoos or rinses. It is often mixed with other plant dyes, such as indigo, turmeric, and senna, to change the color. Allergy to henna is much rarer than allergy to permanent hair colors. It is also considered a conditioning treatment. Using a plant-based color, specifically henna, can cause problems later when trying to do a permanent wave (perm) and other permanent hair color. Discoloration can occur on hair that has been previously tinted with henna; hennaed hair typically cannot be curled. Breakage could also be an issue.Men's Hair Color
This hair color is formulated to fit men only. It will naturally darken or blend gray hair in only ten minutes. 100% natural looking with results lasting up to six weeks.Special effects
Special effects include highlighting and vivid, unusual hair colors such as green or fuchsia. Highlighting can range from temporary to permanent, using the techniques listed above and a special application process. The techniques required to apply highlighting can be difficult for an individual to perform upon him/herself. One can create looks that range from subtle highlights acquired during a day at the beach, to more dramatic looks, such as bold, chunky highlights. The more exotic, bright dyes typically contain only tint, and have no developer. These are typically sold in punk-themed stores (such as comic book and music stores), but are rarely available at commercial hair dressers. Colors range from blood red to seafoam green. Many shades are blacklight reactive. Individuals with darker hair (medium brown to black) are advised to use a bleaching kit prior to tint application for the full effect of the color. Some people with fair hair may benefit from prior bleaching as well, as the yellow undertones of blonde hair can make blue dye look green. These dyes are less permanent, and tend to "bleed" onto other fabric even when dry. Users should anticipate staining of light-colored pillows for a week or so after application.Block Coloring
Is a technique used to create dimension in hair color. an example would be dark color through out the bottom, blond color through the middle area and dark color again on top. it is a dramatic look although it can be done with subtle colors for a softer appearance.Pigment
There are two types of pigment that gives hair its color, eumelanin and phaeomelanin . Eumelanin is black, and pheomelanin is red. All humans have pheomelanin in their hair. How dark it is depends on how much eumelanin is present. A low concentration of eumelanin in the hair will give blonde hair, more eumelanin will give it a brown color, and much higher amounts of eumelanin will result in black hair. Eumelanin in low concentrations causes a yellow tone, in higher concentrations creates a brown color. Pheomelanin is more chemically stable than eumelanin, so it breaks down more slowly when oxidized. It is for this reason that Egyptian mummies have reddish hair, as the pheomelanin is still present but the eumelanin has broken down. This is also the reason bleach will cause darker hair to turn red as it is processing, when it has broken down the eumelanin quickly but acts more slowly on the pheomelanin. As the pheomelanin breaks down, the hair will then become orange, then the chemicals turn it yellow.Common Hair Colors
Natural hair color is generally blond, red, brown, or black depending on the ethnic origins of the person in question. Hair color is genetically associated with certain skin tones, eye colors, and disorders such as skin cancer or albinism in persons with blond or red hair.Black hair is the most common. Black hair is found in people of non-European heritage most commonly, but occurs in people of all backgrounds and ethnicities. It has large amounts of eumelanin and is less dense than other hair colors. It can be almost completely black or very deep black with different hair texture depending on the person and the ethnicity. For example most people of East Asian descent have straight black hair, while people of sub-Saharan African descent generally have thick, coarse hair. The many black-haired Caucasoids of the Mediterranean, Middle East, North Africa, South Asia, and the British Isles exhibit practically all hair forms but wooly.
Brown hair is also found all over the world. Brown hair has more eumelanin than blond hair but also has much less than black. Brown-haired people have medium-thick strands of hair. A brown-haired male is a brunet; a female is a brunette.
Blond hair is a relatively rare human phenotype, occurring in approximately 2% of the world population with the majority of natural blondes being white. Blond hair ranges from nearly white (platinum blond, tow-haired) to a dark golden blonde. Strawberry blond is a rare type: a mixture of blond and red hair. Blondness is a recessive gene. Blond hair can have almost any proportions of phaeomelanin and eumelanin, but both only in small amounts. More phaeomelanin creates a more golden blonde color, and more eumelanin creates a "dishwater" or ash blonde. Natural blondes have the thinnest strand of hair. Red hair is the least common hair color. It ranges from vivid strawberry shades to deep auburn and burgundy.
Red hair is caused by a mutation of the Mc1r gene and is believed to be recessive. Red hair has the highest amounts of phaeomelanin and usually low levels of eumelanin. Natural redheads have the thickest strands of hair.
Effects of Aging on Hair Color
A change in hair color typically occurs naturally as people age, usually turning their hair from its natural color to grey, then to white. More than 40 percent of Americans have some grey hair by their fortieth birthday, but grey hairs can appear as early as the teens and twenties for some, or even in childhood. The determination of when someone begins greying, whether it comes with aging or prematurely, seems to be almost entirely based on genetics. Sometimes people are born with grey hair because it is passed down genetically. Many people use hair dye to disguise the amount of grey in their hair. The change in hair color is caused by the gradual decrease of pigmentation that occurs when melanin ceases to be produced in the hair root, and new hairs grow in without pigment. Two genes appear to be responsible for the process of greying, Bcl2 and Mitf. The stem cells at the base of hair follicles are responsible for producing melanocytes, the cells that produce and store pigment in hair and skin. The death of the melanocyte stem cells causes hair to begin going grey.There are no special diets, nutritional supplements, vitamins, nor proteins that have been proven to slow, stop, or in any way affect the greying process, although many have been marketed over the years. This may change in the near future, however. French scientists treating leukemia patients with a new cancer drug noted an unexpected side effect: some of the patients' hair color was restored to their pre-grey color.
A 1996 British Medical Journal study conducted by J.G. Mosley, MD found that tobacco smoking may cause premature greying. Smokers were found to be four times more likely to begin greying prematurely, compared to nonsmokers in the study.
Genetics
The genetics of hair color are not yet firmly established. According to one popular theory, at least two gene pairs control human hair color. One gene, which is a brown/blonde pair, has a dominant brown allele and a recessive blonde allele. If a person carries the brown allele, they will have brown hair; otherwise, they will be blonde. This also explains why two brown-haired parents can produce a blonde-haired child. The other gene pair is a not-red/red pair, where the not-red allele (which suppresses production of phaeomelanin) is dominant and the allele for red hair is recessive. Since the two gene pairs both govern hair color, a person with two copies of the red-haired allele will have red hair, but it will be either auburn or bright reddish orange depending upon whether the first gene pair gives a brown or blonde hair color respectively. The recessive genes for both brown/blonde and red hair are found nearly exclusively in populations of white people. However, the two-gene model cannot explain the various shades of brown, blonde, or red which may occur (for example, platinum blonde versus dark blonde/light brown), or why one blonde child's hair might turn brown as he grows up while another blonde child's hair does not. There are several gene pairs that control the light versus dark hair color in an accumulative effect. Therefore, the more of these that are dominant, the darker the hair will be.