Colour constancy is a concept in cognitive psychology that refers to the ability of the human brain to perceive colours as being consistent even under varying lighting conditions. This means that an object’s colour remains constant despite changes in the amount and quality of light that falls on it.

Why Is Colour Constancy Important?

Colour constancy plays a crucial role in our perception of the world around us. Without it, we would not be able to accurately identify objects and make sense of their colour in different lighting conditions. For example, if we were to see a banana under blue light, without colour constancy, we might perceive it as being blue rather than yellow.

How Does Colour Constancy Work?

Colour constancy is achieved through a combination of processes in the brain and the eyes. The retina of our eyes contains two types of cells called rods and cones. Rods are more sensitive to low levels of light while cones are responsible for detecting colour.

When light enters our eyes, it is first filtered through the lens and then projected onto the retina at the back of our eyes. The cones on our retina detect different wavelengths of light and send signals to the brain which processes this information to produce a perception of colour.

However, because different lighting conditions can alter the amount and quality of light that falls on an object, this can cause changes in how much light each cone detects. To compensate for these changes, our brains use information from neighbouring cones as well as information about the overall lighting conditions to adjust how it perceives colours.

Theories Of Colour Constancy

There are several theories about how colour constancy works:

Limitations Of Colour Constancy

While colour constancy is a remarkable ability, it does have its limitations. For example, it is less effective under extreme lighting conditions such as in very dim or very bright light. Additionally, certain types of lighting such as fluorescent lighting can make it difficult for our brains to achieve colour constancy.


In conclusion, colour constancy is a complex process that plays an important role in our perception of the world around us. It allows us to perceive colours consistently even under varying lighting conditions which is crucial for identifying objects accurately. While not perfect, our brains have adapted to this challenge and continue to work towards producing an accurate perception of the world around us.