A color anomaly

A thread from the other day about color got me thinking about a quirky aspect of additive (RGB) color that I suspect is skipped over in university design classes when color theory is discussed.

As most of us know, color receptors in our eyes see the red, green, and blue wavelengths of light. Overlaps of these three colors enable us to perceive all the in-between colors. Using a glass prism, it’s easy to separate white light into all its component colors of the visible spectrum.

When we overlap, for example, red light and green light, we get a color halfway in between — yellow. Add yellow and red light together and it produces a new color halfway in between — orange. These new colors are more or less the average of the adjacent colors, but there’s an exception on the color wheel.

When we bend the spectrum around into a color wheel, there’s an obvious problem. All the colors blend into each other nicely except the violet and red end-of-spectrum colors, which abruptly crash into each other because those wavelengths aren’t adjacent to each other in the spectrum.

If we did blend the two end colors, we would logically create a color halfway in between in keeping with how the other colors work. However, using this formula that color would logically be green, but the color green is already used to allow us to perceive the wavelengths in the center of the spectrum.

To make up for the visually problematic oddity created by these non-adjacent endpoints in the light we see, our brains do something rather interesting — we create a color that doesn’t exist on the spectrum, then we adjust the rest of how we perceive the entire spectrum to accommodate this extra invented non-spectrum color. This workaround color is what we call magenta.

Maybe I’ve had too much time on my hands today. It’s snowing outside and I’m bored.


True pink doesn’t exist on the electromagnetic spectrum.

It’s perceived through rods and cones in the eye.
Funny enough, people think that women see pink differently as they have more rods/cones than men.

And a study I read says it might be back to how we evolved from cave dwelling days, where men were hunter gathers and women were stay at home (breast feeding) minding kids (as men couldn’t possibly breast feed) so the relationship of division of labour was fair.

And as a result women spent more time in low light conditions - which increased their ability to perhaps see in the dark - and over time developed more rods/cones than men.

As far as I know - pink is perceived differently by women.

I don’t know about the cave-dwelling stuff - it’s a stretch if you ask me.
But it’s definitely down to Rods/Cones and it’s proven women have more.

Women tend to have more cones. Men more rods. Some women, a very small percentage, have one more set of cones, giving them a far wider spectrum of colors (tetrachromatic…I swear some of my clients have these! LOL!)

Stay at home moms like in some dark cave, teepee or hut? Someone had to go pick the berries, catch fish, knock over birds/rabbits with a stick, get the firewood and water, prepare the game, etc. They carried the kid along with them, not staying at home poking the fire and breast feeding the baby. Not buying it. Certainly not from one little project conducting research on today’s humans at Brooklyn College. They should have asked those kids if they played video games, LOL. I bet the males that do far outnumbered the females, and a good player, of either sex, is gonna rank high on the ability to perceive and track fast objects. :slight_smile:

There’s a way to see that pink. If you stare directly at the green circle for about 60 seconds, then immediately avert your gaze to the white circle, the white circle will fill with a pink that doesn’t correspond to any wavelength in the spectrum.

Instead, the color emerges as the result of fatiguing the cones in your eyes that normally see green. The effect begins to fade after a few seconds as those cones recover.


That afterimage is probably red (opposite green), not really pink.
Despite this saying it was rendered in 1994, I remember seeing this one in the 60s in a Time Life science series book

The opposite and complementary color of green is the secondary color produced by the combination of red and blue light: magenta.

I suspect that when the green-sensing cones become fatigued and one looks at white light, some of the green isn’t perceived as well as the red and blue. This absence of green skews the white to the secondary color created by red and blue to produce an extra-bright, light magenta, which looks pink.

I haven’t seen anything written about this, but seeing white would seem to require that the balance between the red, green, and blue sensing cones be precisely calibrated in order to see white without the white being shifted to the complement of whatever color-sensing cone was deficient. This makes me wonder how color-blind people see white. Then again, I don’t know what causes color blindness, so now I’m going to have to look that up. Yeah, I’m headed down a time-killing rabbit hole with this.

I think I’ve posted a link to some page or other from this before but seriously…

go knock yourself out.

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Well, there’s a half day’s worth of reading. Thanks (I think). :wink:

Oh, there’s a lot more than half a day. Half a month, maybe more.

Most of it makes my head spin, but I still like reading it and having my mind boggled.

Here’s a direct link on this site to some writing about extraspectral hues such as magenta