Melanin is what causes the color to appear in the skin, hair and eyes. But in humans there seems to be a limit to this. For example human hair can be orange(gingers) but not green or blue. iris's can be blue but not yellow or black. What determines the color range of hair and iris's? How can I add (or remove) colors from this range naturally?

The Iris colors I am specifically looking for;

  • Bright Green

  • Silver

  • White

  • Black

    The Hair colors I am specifically looking for;

  • Blue

  • Green

  • White

  • Purple

Edit I am not asking about albinism or other conditions, I am asking about common an natural ways for these colors to appear from birth.

  • $\begingroup$ Human hair can definitely be red. $\endgroup$
    – celtschk
    Commented Oct 14, 2015 at 20:33
  • $\begingroup$ that's more orange than red $\endgroup$
    – TrEs-2b
    Commented Oct 14, 2015 at 20:34
  • $\begingroup$ Anecdotal Evidence: My eyes were orange one morning a few years ago. My eye color changes by the time of year and my mood. It makes filling out forms interesting. $\endgroup$
    – Frostfyre
    Commented Oct 14, 2015 at 20:38
  • 1
    $\begingroup$ You could probably make red hair by adding iron to it, and green hair by adding magnesium. The hemoglobin in our blood is red because of the iron ion it contains, whereas chlorophyll is green thanks to its magnesium ion. Aside from the iron/magnesium ion in the center, hemoglobin and chlorophyll is exactly identical, both chemically and structurally. $\endgroup$
    – Nolonar
    Commented Oct 14, 2015 at 20:42
  • 2
    $\begingroup$ Thats a good comment, how about turning it into an answer $\endgroup$
    – TrEs-2b
    Commented Oct 14, 2015 at 20:43

3 Answers 3


Completely white eyes, I don't know, but I've known two people with icy blue eyes, almost silver, one of the prettiest things I've seen.

As for white hair, I had a friend in grade 1 with natural white hair but not albino. Of course both are caused by melanin deficiency, and you said you didn't want that. However for white any way that's the most effective way, and mind you, all three people mentioned were tanned, not albino.

As for black eyes, they exist, they are rare but they exist and they are from excessive amounts of melanin. Basically really really dark brown you could say that doesn't count but you wont get any closer.

One thing about your question doesn't quite make sense: you want 'common and natural ways' when those hair and eye colours are not common and mutation is a natural occurrence (red hair and blue eyes being mutations ie. blue eyes are from not producing enough melanin after birth, in which most babies have blue eyes).

that being said, if we use mutations an deficiencies, we can achieve your proposed colours. since there can be yellow/golden parts in irises (mine for example) it could be assumed that mixing of yellow and green could make light green. the golden part is caused by aging, and is only a ring around the pupil so i guess it still doesnt count.

the other thing that factors colour in eyes is light refraction, if the structures were 'weird' enough, you could have iridescent irises if you wanted. some blue eyes look violet in the right light. the same goes for hair, if you had hair that say, had microscopic holes in it that refracted the light like the blue morpho butterfly's wings, mybe you could have strange coloured hair at the right angle.


For human hair and eyes the best way to add colors to the natural range would be if your cells would naturally produce other types of pigment. It would also be possible to produce colors by having structures that are the same size as the wavelength of those colors. You could get green hair for instance by having a yellow pigment combined with structures in the hair that are the same size as the wavelength of blue light. Blue hair also could either be produced by having a blue pigment or by having structures that are the same size as the wavelength of blue light.


Technical detail: My eyes are naturally light green enough to be almost yellow.to wit So I'm walking proof human beings can have bright green irises and approaching yellow in sunlight. As for the other iris and hair colors, animals can have fur and eye color not normally possible for people by having different pigments. If the characters in your world had genes that allowed for pigments normally absent from people in reality, they could 'naturally' have those colors.

Now I'm not technically adept enough to know what pigments those might be nor in which proportions but check out an avian or primate anatomy book and I'm confident you can get that information.


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