The picture for this article is a block of colour with no alternate text or title. Assuming you can see it, think about what you would call it before you read on.
If you described the colour above to someone else it’s likely they would imagine something quite different. You could describe it as lavender, lilac, mauve or pale purple but in each case there’s no universal meaning for these words.
If you’re more technically minded you could sample the colour to discover its hex value is #9B90C8 but if someone else used that value to create an identical image there’s no guarantee they would see the same thing or give it the same name. This is because our perception of colour is relative, subjective and learned.
Firstly, each colour we perceive is relative to the other colours that surround it. The most powerful example of this is the illusion of yellow that’s created when you move brown into the shade. Brown doesn’t appear in the rainbow and we only perceive brown objects based on the brightness or darkness of other objects in the vicinity.
Secondly, each colour we perceive is subjective because each pair of eyes is different. Some people are colour blind which suggests a disability, although research has found there are some advantages such as being able to spot certain types of camouflage. Some people can see ultraviolet and it’s also been suggested others have four sets of colour receptors instead of the usual three.
Finally, each time we perceive a colour we relate it to what we’ve learned, some of it useful and some of it less so. We learn the names of seven colours of the rainbow where in reality a full spectrum of light has as many colours as you choose to name. Many of us learn that purple and violet are synonymous. Many of us leave school with the idea of red, yellow, blue and green being the four primary colours.
However much you learn, it’s not possible to recall the name of a colour in the same way that you can the name of a musical note. There is no equivalent in vision to perfect pitch. So if I were to reveal that Pantone call the block of colour on this page 16-3823 Violet Tulip, their colour of the year 2004, you might like to remember it but you could never be certain you were seeing the same colour again.
Perhaps one thing we can agree on is black as it’s something we all experience when no visible light reaches the eye. But even here there are differences. I live near Sean Kanavan, a blind guerilla gardener who plants flowers in his street. As he went blind later in life he remembers colour and always likes to hear how his hollyhocks have turned out. But to someone born blind, blackness and nothingness are quite different as Richard Gregory explains in his book Eye and Brain:
The sensation given to us by the absence of light is blackness; but to the blind it, it is nothingness. We come nearest to picturing the world of the blind, who have no brightness and no black, by thinking of the region behind our heads. We do not experience blackness behind us: we experience nothing, and this is very different from blackness.