I’ve been amazed by the massive response to my article, “Magenta Ain’t A Colour“, which was first published at Null Hypothesis and then subsequently on Biotele.com. I was also interested to read the response by Chris Foresman at Ars Technica. However, I think certain confusions have arisen, mostly due to the title of the article, and I’d like to set the record straight.
Firstly, I agree that the title is misleading – it was not my original title, and was chosen by the editorial team at Null Hypothesis. My original title was, “Why is Magenta not in the Light Spectrum?” This would have been a more accurate, if perhaps less catchy, title.
Secondly, I never set out to imply that Magenta was not a colour. All I wanted to point out was that, unlike most fully-saturated colours, magenta cannot be pin-pointed in the light spectrum, i.e. there is no single wavelength of light that can be said to be interpreted by our eyes as ‘magenta’. Of course there are other colours that are also constructed from mixtures of wavelengths, but generally we can group colours into ‘reds’, ‘oranges’, ‘yellows’, ‘greens’, blues’, ‘violets’ and ‘magentas’. But red, orange, yellow, green, blue and violet can each be represented by a single wavelength and magenta cannot. It is ‘extra-spectral’.
Thirdly, what I was really trying to get at with my article was how the actual physical world and how we interpret it can have subtle differences. For example, we experience colour as a closed, continuous loop, going from red to yellow to blue to violet to magenta and back to red again. But the light spectrum is not a closed loop. It is open-ended, going from shorter wavelengths to longer ones. Red wavelengths are next to infra-red wavelengths. Violet wavelengths are next to ultra-violet wavelengths. In absolute physical terms, where is magenta? The answer is that only in the visual interpretation of light does magenta appear.