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What is Vs real hair color?

Red hair color: The myth

Some people have red hair, and some have hair that is various shades of blond or brown. The myth is that red hair is determined by a single gene, with the allele for red being recessive to alleles for other colors.

The reality

Hair color as a character

Hair color is determined by the amount of eumelanin (which is dark brown) and pheomelanin (which is reddish). The amount of eumelanin ranges continuously from very little, producing light-blonde hair, to large amounts, producing black hair. People with large amounts of pheomelanin have red hair, which can range from pale red («strawberry blond») to bright red to reddish brown.

Most studies divide hair color into a small number of categories, such as blond, red, and brown. Reed (1952) criticized the subjectiveness of this approach and used a reflectance spectrophotometer to measure the amount of light reflected by hair at different wavelengths. He found that there was no clear separation of hair into two categories; instead there were some individuals with intermediate hair that could not easily be classified as red or non-red. Reed (1952) also examined hair under a microscope and found the reddish pheomelanin granules that are common in red hair were also in some individuals with brown hair. This suggests that when the red pheomelanin pigment is present, whether a person has red hair is determined by the amount of brown eumelanin pigment that the person also has.

Family studies

The variety of hair colors makes it difficult to summarize the results of family studies in detail. Davenport and Davenport (1909) found numerous examples of two brown-haired parents having red-haired offspring, which would suggest that it is determined by a recessive allele, but Neel (1943) found 13 out of 114 offspring of two red-haired parents to have non-red hair. Reed (1952) reviewed the various hypotheses that had been proposed, including that red was recessive; that red was dominant; that red was dominant, but could be masked by brown; or that red was usually recessive but could sometimes be dominant.

Molecular genetics

Valverde et al. (1995) surveyed DNA sequence variation in the melanocortin 1 receptor (MC1R) gene. They found several amino acid variants that were found in red-haired people but rare in non-red people. Box et al. (1997) identified the three most common amino acid polymorphisms that are associated with red hair: R151C, R160W, and D294H. This shorthand means that the common amino acids at positions 151, 160 and 294 in the protein are arginine (R), arginine, and aspartic acid (D), while the amino acids cysteine (C), tryptophan (W), and histidine (H) are found in redheads. Most alleles have only one of these three red-associated amino acids; for example, some alleles have cysteine at position 151 but arginine and aspartic acid at positions 160 and 294.

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There are a large number of rare amino acid polymorphisms in the MC1R gene, some of which may also be associated with red hair (Beaumont et al. 2007). Sulem et al. (2007) surveyed genetic variation throughout the genome of a large sample of Icelanders and found that MC1R is the only gene with a strong association with red hair. However, knowing the genotype of an individual at the MC1R locus is not enough to predict whether they have red hair. Beaumont et al. (2007) found that only 74% of individuals who were homozygous for tryptophan at position 160 have red hair, while 4% of individuals who were heterozygous for this amino acid had red hair. Box et al. (1997) found five pairs of dizygotic twins which had identical genotypes for the MC1R gene, yet one twin had red hair and the other didn’t. Sulem et al. (2007) used the variation at the MC1R gene to try to predict hair color, and about a third of the individuals who were predicted to have red hair actually had blond or brown hair.


The alleles associated with red hair are fairly common in northern European populations; in Britain and Ireland, the R151C allele has a frequency of about 10 percent, while R160W and D294H are at 9 and 2 percent (Gerstenblith et al. 2007). Red hair is rare in other populations, which has led to speculation that the alleles for red hair were favored by selection by differing amounts of ultraviolet radiation, since red hair is associated with pale skin (Jablonski and Chaplin 2010) and is most common in areas with gloomy winters. Harding et al. (2000) applied several statistical tests for DNA sequence data and found no evidence that the large amount of amino acid variation at MC1R resulted from positive selection; in particular, the large number of amino acid sites that vary within human populations are comparable to the large number of amino acid differences between human and chimp MC1R. Harding et al. (2000) did not find any amino acid variation within African populations, so they concluded that there is strong negative selection there (new amino acid mutations are selected against). They concluded that the variation outside of Africa reflects a relaxation of negative selection allowing new alleles to drift in frequency, rather than new alleles being favored. In contrast, Savage et al. (2008) concluded that MC1R was affected by positive selection, based on the greater geographic variation in allele frequency than most human genes, greater levels of polymorphism, and an unusually large number of low frequency polymorphisms.

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Red hair color is not an example of a simple genetic trait. While the amount of red pigment may be mainly determined by one gene (MC1R), there are a large number of different MC1R alleles, and other genes affecting the amount of brown pigment that plays a major role in determining hair color. The complicated genetics means that it is possible for two red-haired parents to have non-red-haired children.


Beaumont, K. A., S. L. Shekar, R. A. Newton, M. R. James, J. L. Stow, D. L. Duffy, and R. A. Sturm. 2007. Receptor function, dominant negative activity and phenotype correlations for MC1R variant alleles. Human Molecular Genetics 16: 2249-60.

Box, N., J. Wyeth, L. O�Gorman, N. Martin, and R. Sturm. 1997. Characterization of melanaocyte stimulating hormone receptor variant alleles in twins with red hair. Human Molecular Genetics 6:1891�1897.

Davenport, G. C., and C. B. Davenport. 1909. Heredity of hair color in man. American Naturalist 43: 193-211.

Gerstenblith, M. R., A. M. Goldstein, M. C. Fargnoll, K. Peris, and M. T. Landi. 2007. Comprehensive evaluation of allele frequency differences of MC1R variants across populations. Human Mutation 28: 495-505.

Harding, R. M., et al. (11 co-authors). 2000. Evidence for variable selective pressures at MC1R. American Journal of Human Genetics 66: 1351-1361.

Jablonski, N.G., and G. Chaplin. 2010. Human skin pigmentation as an adaptation to UV radiation. Proceedings of the National Academy of Sciences 107: 8962-8968.

Neel, J. V. 1943. Concerning the inheritance of red hair. Journal of Heredity 34: 93-96.

Reed, T. E. 1952. Red hair colour as a genetical character. Annals of Eugenics 17: 115-139.

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Savage, S. A., M. R. Gerstenblith, A. M. Goldstein, L. Mirabello, M. C. Fargnoll, K. Peris, and M. T. Landi. 2008. Nucleotide diversity and population differentiation of the melanocortin 1 receptor gene, MC1R. BMC Genetics 9: 31.

Sulem, P., et al. (25 co-authors). 2007. Genetic determinants of hair, eye and skin pigmentation in Europeans. Nature Genetics 39: 1443-1452.

Valverde, P., E. Healy, I. Jackson, J. L. Rees, and A. J. Thody. 1995. Variants of the melanocyte-stimulating hormone receptor gene are associated with red hair and fair skin in humans. Nature Genetics 11: 328-330.

OMIM entries for red hair and MC1R

This page was last revised December 8, 2011. Its address is It may be cited as pp. 37-39 in: McDonald, J.H. 2011. Myths of Human Genetics. Sparky House Publishing, Baltimore, Maryland.

©2011 by John H. McDonald. You can probably do what you want with this content; see the permissions page for details.

Hair colour numbering system

When it comes to changing the colour of your hair – knowing some basic information about how hair colour charts work can be fundamental in understanding the options presented to you in-salon.


Your L’Oréal Professionnel colourist will use our international colour numbering system during your bespoke in-salon consultation to identify which depth and tones/reflects will best suit you and your hair. We have decoded the hair colour numbering system: one of the key tools which will help you better understand the complexity that goes into your hair colour service in-salon.

There are up to 4 figures in a hair colour number, up to 2 before the decimal point and up to 2 after the decimal point. For example, 3, 5.8, 6.13 and 10.21 are all L’Oréal Professionnel hair colour numbers.

Understanding Hair Colour Charts


The level system is made up of 10 numbers which help determine the depth level of your natural hair. 1 is black, 5 is light brown, 6 is dark blonde, 7 is blonde and 10 is the lightest blonde. Your L’Oréal Professionnel colourist will analyse your hair and assess your natural base colour in-salon.

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The first number which appears on the colour chart is the base colour. This number indicates the base level of the shade you would like to achieve. It shows how light or dark the colour is.


Next your colourist will look at the second and third numbers on the colour chart that appear after the period mark. These numbers indicate the primary and secondary reflects/tones that are present in the colour.

For example,.1 = Ash, .2 = Iridescent, .3 = Golden, .4 = Copper

This system also allows your colourist to neutralise the colour, so for example to avoid a blonde hair colour from becoming too warm; they could add more .2 (violet) or .1 (blue) to counteract the yellow or orange tones that appear naturally.

The outcome of your final target shade will also be influenced by several other factors that need to be assessed by your L’Oréal Professionnel colourist such as undercoat and distribution of pigment.

Whether you have a specific colour in mind or are in need of some inspiration, your L’Oréal Professionnel colourist can offer you a bespoke service to identify the best hair colour for you. Taking into consideration your natural hair colour, skin tone and eye colour they will create a personalised shade that can help emphasise and illuminate your features. Ask for a colour consultation at your nearest L’Oréal Professionnel salon today to receive your personalised and tailored colour.

Inspired? Discover what hair colours suit you with our virtual hair colour try-on tool .

Color Selector

Colour Quiz

Colour selection is a crucial step to achieving a result you’re besotted with. Our colour selector will help you get your permanent colour selection right first time. Well, it will as soon as our developers have finished working their magic. Watch this space for our colour selector COMING SOON.

In the meantime, here are our top tips on how to select your perfect shade.

How to select your perfect permanent hair dye

Tints of Nature permanent shades will take your hair any shade darker and will lift your hair by one shade. To find your perfect Tints of Nature colour follow these easy steps:

1. Using our natural shade range as a guide (1N to 10N), select a colour that best represents your natural hair colour. You can see our colour swatches here.

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2. Choose any colour within that shade level, any shade darker, or up to one shade lighter. For example:

  • If 5N is your natural shade or close to, you can use any colour within the 5 range or darker.
  • If you want to lift your hair by one shade you can use 6N. Due to the gentle nature of our colour formulations, hair can only be lifted by one shade.
  • To achieve a higher lift you will need Tints of Nature’s ammonia-free 3-in-1 Lightener Kit, suitable for medium brown to blonde hair.

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How to select your Henna Cream semi-permanent hair dye

Tints of Nature semi-permanent Henna Cream shades are perfect if you’re looking for a temporary colour change, looking to experiment with a new shade or add depth to your existing colour.

Henna Cream shades are not capable of lifting the colour of your hair, but are designed for staying on your current base shade or for going darker. It’s easy to find your perfect shade with Tints of Nature colour:

1. Simply choose any colour that’s similar in depth, or darker, than your natural or pre-coloured hair and enjoy! But remember, Henna Cream semi-permanent hair dye won’t lighten. So, if you have dark brown hair and you choose Golden Brown or Golden Blonde Henna Cream, all you’ll get is lovely shiny hair. You won’t see any colour change.

It’s as easy as that!

If you want to lighten your hair go for a permanent hair dye or pre-lighten your hair with our ammonia-free Lightener Kit before colouring.

We’re always here to help

Whether you’re dyeing your hair yourself for the first time, or you’re a seasoned DIY hair dye pro we’re here to help.

Our live chat is available in office hours and we always love hearing from you over the phone or email as well.

If you’re after a super-bright vibrant colour or on-trend pastel hue you can read all about our Bold Colours in this helpful blog.

You can also check out our tip tips which cover everything from how to cover stroppy grey hairs, to how skin test.

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