IS PURPLE A REAL COLOUR?
Let me explain why purple doesn’t *technically* exist and what this means for the way we see the world.
*PLEASE NOTE* I am from the UK so I will use the British spelling of ‘Colour’ as opposed to the US spelling ‘color’.
I don’t know about you, but I can’t help questioning reality on a daily basis.
How do we know what is real?
How do we know that what you are seeing is the same as what I can see?
Well the short answer is, we don’t.
I often used to wonder this about colours in particular. Then, when learning more about colour theory for my art practice, I discovered that the colour we call ‘purple’ does not technically exist.
At least, not in the same way as other colours.
Before I explain further, I just want to clarify that often, the term ‘purple’ is used as a name for all colours that fall in between red and blue. It is only *certain shades* of what we may consider ‘purple’ that do not technically exist.
To illustrate this point, please take note of this image with a huge variety of shades that could all come under the umbrella of ‘purple’.
(Some of these shades are extremely dissimilar and I really think that we should upgrade our colour vocabulary!)
The shade of purple which DOES technically exist here is violet.
Sir Isaac Newton’s Theory of Light revealed that the color spectrum is made up of red, orange, yellow, green, blue, indigo, and violet. While violet is a genuine color within the spectrum of light, shades like magenta, fuchsia, orchid and heliotrope are not. Since purple is an over-arching term for this combination of shades, it both is and isn’t real, depending on the exact shade someone might be referring to. The image below shows the type of purple I am referring to versus violet.
So, why are these other shades of purple not actually ‘real’ colours?
Unlike the other colours we see, purple (specifically magenta) doesn’t have a wavelength, and does not exist on the light spectrum. It is not a ‘spectral’ colour.
Going back to Sir Isaac Newton’s theory of light, this makes sense when you think of a rainbow. A rainbow is the refraction of light through water droplets, breaking up white light into 7 different visible wavelengths; or colours, as previously mentioned. However, purple is not there.
Look at the spectrum of light to see what I mean – or, try to find it next time you see a rainbow.
The reason for this is that our brains actually just invent purple when an equal mix of red and blue light hits our eyes.
To understand how this works, let me first briefly explain how our eyes receive colour.
I am by no means an optician, but I do know that we have cones cells in our eyes which are what allow us to perceive colour.
We have 3 types of cone cells, and each type is in charge of a different colour – so we have red-sensing cones, green-sensing cones and blue-sensing cones in each eye.
If we see something red, then our red-sensing cones start to fire up and send signals to the brain, letting us know that what we are seeing is, indeed, RED.
The same goes for green and blue.
Now, if we were to look at something yellow or orange, then both our red-sensing cones AND our green sensing cones would fire, as these colours fall in-between red and green on the spectrum of light.
Again, if we see any kind of cyan, turquoise or light-blue then both our green-sensing cones and blue-sensing cones would fire at once, because these colours are between green and blue on the spectrum of light.
Now, look again at the spectrum of light featured below. What colour falls between blue and red?
The correct answer here is green.
However, we already have green-sensing cones in order to see that colour.
So, if our red-sensing and blue-sensing cones are firing at the same time, which other colour could be in-between them?
Well, as the spectrum of light is linear, there actually isn’t one.
Instead, blue briefly continues into violet before the frequency increases further into ultra-violet, X-rays and then Gamma rays.
In the opposite direction, after we see red, the frequency decreases, creating longer wavelengths and moving into what we know as infrared, microwaves and radio waves.
So, since there is nothing between red and blue on the spectrum of light (apart from the green that is already taken care of) –
what happens when our brain receives a signal from both the red-sensing and blue-sensing cones at the same time?
Well, from my understanding, it essentially panics and makes up purple.
Et voila: that is why purple is not a real colour.
It doesn’t have a wavelength / frequency and, as far as we know, only exists in our minds.
While that may have answered some questions, for me, it made me start asking 1083828219 more.
Which is often the reason I make my artwork anyway; to express some sort of visual conclusion towards the unanswerable questions of life.
I actually ended up doing a series of purple spiral drawings based on this fact, which I recently turned into a poster!
So, even though the originals aren’t available, you can still sit & question reality from the comfort of your own home with my artwork 😉
