Can cats see colours?

Yes, but rather poorly, is the answer. In the first half of this century scientists were convinced that cats were totally colour-blind and one authority reworked a popular saying with the words: 'Day and night, all cats see grey." That was the prevailing attitude in the 1940's, but during the past few decades more careful research has been carried out and it is now known that cats can distinguish between certain colours, but not, apparently, with much finesse.

The reason why earlier experiments failed to reveal the existence of feline colour vision was because in discrimination tests cats quickly latched on to subtle differences in the degree of greyness of colours and then refused to abandon these clues when they were presented with two colours of exactly the same degree of greyness. So the tests gave negative results. Using more sophisticated methods, recent studies have been able to prove that cats can distinguish between red and green, red and blue, red and grey, green and blue, green and grey, blue and grey, yellow and blue, and yellow and grey. Whether they can distinguish between other pairs of colours is still in dispute. For example, one authority believes that they can also tell the difference between red and yellow, but another does not.

Whatever the final results of these investigations one thing is certain: colour is not as important in the lives of cats as it is in our own lives. Their eyes are much more attuned to seeing in dim light, where they need only one-sixth of the light we do to make out the same details of movement and shape.