Tests on people who are colour blind reveal that they see a variety of colours as rich as those with normal sight, research has found. Scientists investigated the most common form of colour blindness which affects six per cent of men, who are described as “green weak”.

They found support for an idea that dates to the Second World War that they are better at penetrating camouflage. Men who have this form of colour blindness are poor at noticing small differences in the red, orange, yellow and green region of the spectrum. This form of colour blindness, known as deuteranomaly, enhances the perception of some colours outside the usual palette of descriptions.

The findings were published in Current Biology by Prof. John Mollon, Jenny Bosten and Jo Robinson of Cambridge University. The team asked deuteranomalous and “colour-normal” individuals to rate the differences between pairs of colours that were predicted to look different to deuteranomalous men but to appear the same to those with normal colour vision.

A statistical analysis of the results suggested that people who are colour blind live in a world with a “colour dimension” that is inaccessible to those with normal vision. Mollon said that, in one sense, we are all colour blind. Surfaces present an infinite variety of reflection spectra. But our colour vision depends on just three types of colour sensors in our retina.

3 facts about those who confuse shades

1: Being colour-blind can make it tricky to match your shirt and pants, but it’s not a serious problem. People who are colour-blind can do normal work, even drive. Most color-blind people can’t tell the difference between red or green, but they can learn to respond to the way the traffic signal lights up. The red light is generally on top and green is on the bottom.

2: Colourblindness doesn’t mean people can’t see any color at all. It only means that they have trouble seeing the difference between certain colours. Colour blindness is almost always an inherited problem. Boys are far more likely to be colourblind. In fact, if you know 12 boys, one of them is probably a little colour-blind.

3: Eye doctors (and some nurses) test for color blindness by showing people a picture made of different coloured dots. If a person can’t see the picture or number within the dots, he or she may be declared color-blind.