Is Pink a Color?
MinutePhysics, a popular YouTube channel, posted a video a little while back saying that there is no pink light. This seems to have sparked a debate over whether or not pink is a color - an issue not really brought up by the original video. So, is pink a color? As usual, science is more complicated than you’d initially believe.
Since this is a physics blog, let’s go with the usual physical understanding of what ‘color’ is. Every color, effectively, is just a certain frequency of light. Electromagnetic radiation is characterized by its wavelength, frequency, intensity, etc. When the wavelength is within the visible spectrum (the range of wavelengths humans can visually perceive, approximately from 390 nm to 700 nm), it is known as “visible light,” a range which we breakdown as Roy G. Biv.
There is no single frequency which our brains correspond to “pink” light. Then, how does pink exist? Effectively, pink is a combination of red and violet light - two colors from opposite sides of the visible spectrum. Since these two colors are literal opposites on the visible spectrum, pink could not exist as a fundamental frequency in nature (if you tried to average out the frequencies and “mix” them, you’d arrive at a color somewhere near the middle of the spectrum, around yellow or green). Thus, pink isn’t a fundamental frequency floating out there in space - a single frequency that we could call “pink” doesn’t exist.
Hold on Tumblr bro, Pink obviously exists, I see it on Nicki Minaj all the time!
Yes, yes - what we perceive as Pink does exist on its own, but does that necessarily make it a true color? Will Pink be excluded from the highly exclusive Color Club much like Pluto was ousted from the Planetary Patrol?
Take a second to look around you, you’ll see tons of objects - probably many colored ones. When you look at, for example, a red object - that object absorbs all of the other frequencies except red, and it reflects red back to you. However, when you look at a pink object - you are not seeing pink wavelengths of light. An object would appear pink because wavelengths of both red and violet are being reflected - and our brains perceive it as a new “color,” namely pink.
On a very fundamental level, pink is not a fundamental part of the universe - because no color is. The universe is chock full of electromagnetic radiation, and the only truly fundamental properties of it are wavelength, amplitude, frequency, etc. Color is a phenomenon completely produced by your brain - it’s how we perceive the light. Even different animals perceive light differently than us - like certain animals that can see beyond the visible spectrum, including infrared light. As biologist Timothy H. Goldsmith wrote for Scientific American, “color is not actually a property of light or of objects that reflect light, it is a sensation that arises within the brain.” So, by existing only as a human means of understanding the universe, pink is just as “real” as any other color.
So, there you have it - pink is not a part of the light spectrum, it is the effect of our brains filling the gap between blue and violet, but does that make it any less of a color than anything else?
Let’s look at two common definition for what a color is - one artistic and one scientific.
Scientific Definition: The sensation produced by the effect of light waves striking the retina of the eye. The color of something depends mainly on which wavelengths of light it emits, reflects, or transmits.
Artistic Definition: Color is the element of art that is produced when light, striking an object, is reflected back to the eye.
While there is no fundamental definition of color in all respects, personally, I’d say that pink fits both of these descriptions. Since no color is a fundamental property of the universe, pink does not exist as a part of the visible spectrum, but since all colors are just fabrications of our brain, I have to side with pink here. There are intelligent people on both sides of this debate, and one’s interpretation of definition seems to be how one decides whether to draw the line or not to exclude pink. Where do you stand?