Colour blindness is a condition which affects one in 12 men, in comparison to one in 200 women.
Consequently, men are much more likely to struggle at this test, which involves spotting tiny differences in colours and shades in order to spot patterns (in this case – to spot letters of the alphabet).
There are many different forms of colour blindness, but certain questions in the test are likely to be more difficult for people with dichromacy (difficult distinguishing between two similar colours).
Have a go and see how you get on…