How It Works
The rods and cones in your eyes are unique, and therefore we all perceive colours slightly differently. However, some people cannot discern between one colour and another. Three types of cones – red, green and blue – create the colours we see, while the rods record brightness. People with colour blindness have fewer of certain types of cones and more of another. This means they are more receptive to certain colours than others, and will even be unable to distinguish between some colours. The most common colour confusion is between red and green.