How Many Colours Can You See?

[Mike Farley]

According to PetaPixel, it is around 1 million if you have normal vision, but some people can see considerably more if they have a condition known as tetrachromacy. There are tests you can do which allow you to check your own colour vision.

http://petapixel.com/2016/03/30/people- ... es-colors/

8 bit colour, which is used for JPEG images, allows 16 million hues to be represented, but the chances are that you cannot see them all unless you are a tetrachromat.

[Peter Boughton]

There's a link to a colour test in the article: https://www.igame.com/eye-test/

First time I got to 25 without any errors, second time I got to 26 - apparently that makes me a hawk.

Interestingly, the first 20 or so I spot really quickly - then I start slowing down slightly, and then a purple one appears...

[Rose]

I just got to 25 on my first attempt too...

[GrahamL]

I only managed 14, too many errors when I got to a screen I could only guess at. Could be my Dell IPS calibrated monitor, but more likely due to my colour blindness in part of the red-green spectrum. On the other had I was the only person in the QC lab I worked in as a student who could reliably perform one colorimetric test involving a very subtle change in colour. I'll survive.

Graham