26 Mar 2015

25% of People Have a Fourth Cone (Color Receptor)

, , ,


Professor Diane Derval told me something today that I had not known.

The color nuances we see depend on the number and distribution of cones (=color receptors) in our eye. You can check [the above] rainbow: how many color nuances do you count?

You see less than 20 color nuances: you are a dichromats, like dogs, which means you have 2 types of cones only. You are likely to wear black, beige, and blue. 25% of the population is dichromat.

You see between 20 and 32 color nuances: you are a trichromat, you have 3 types of cones (in the purple/blue, green and red area). You enjoy different colors as you can appreciate them. 50% of the population is trichromat.

You see between 33 and 39 colors: you are a tetrachromat, like bees, and have 4 types of cones (in the purple/blue, green, red plus yellow area). You are irritated by yellow, so this color will be nowhere to be found in your wardrobe. 25% of the population is tetrachromat.

You see more than 39 color nuances: come on, you are making up things! there are only 39 different colors in the test and probably only 35 are properly translated by your computer screen anyway :)

I originally counted colors on the basis of differentiated rectangles I could see, which gave me too many. When I went back and looked strictly at color gradations, I got 39. And I do hate yellow.

Hat tip to Chico Kidd,

5 Feedbacks on "25% of People Have a Fourth Cone (Color Receptor)"


Very, very cool! And LOL for doing exactly what I did. Counted the rectangles. Got 45. Went back, focused on color, got 39.

And yellow. Ick. Okay on flowers but not near me, thanks.

Jerry the Geek

I found 38 distinct color bands, very easily (only 2 or 3 bands required a second look to be certain I was seeing two rather than one). And in fact, Yellow is my favorite color: I painted my house yellow!

On the third hand, I have only 2 yellow items of clothing in my closet, and one of those is a “gimme” tee-shirt from The Yellow Pages book.


I counted 34.

I have one yellow shirt (with brown palmtrees) in the closet. I think it looks nice, but it annoys me when I see it in the edge of my vision when I wear it. Haven’t worn it in years.


I counted 34 but if I looked straight on, some the purple ones melded into one. Which makes sense — while cones are concentrated more at the fovea, there is a lower concentration of the blue cones. If I looked just a tiny a little off to the side, I saw more purple ones.

I’m not sure I own anything yellow. Nope. Nothing yellow. Except a safety yellow-green jacket. I hate sunflowers. I can live with yellow tulips, but love the purple ones. And the only reason I like forsythia is they have beautiful pink leaves in the fall. My dream flower garden would be all purple flowers.


Odd, but the longer I look at it, the more I can see. But the yellow remains one big fat yellow band. With the others, I can see what looks like darker lines of color between the bands, but not always a clear differentiation between two adjacent bands, even though I can see the bands readily.


Please Leave a Comment!

Please note: Comments may be moderated. It may take a while for them to show on the page.

Entries (RSS)
Comments (RSS)
Feed Shark