The Colour Magenta

Colour WheelThe perception of colour is a really tricky topic once you start to look at it closely. While I was working on artwork for Light Log visualisations, trying to represent light data as a full colour spectrum, the more I started to notice that many illustrations of rainbows, spectrum and colour palettes seemed to have something unusual going on…

Of all the wonderful colours we experience, for most of us, our eyes only have colour sensitive cells that respond to three different areas of the electromagnetic spectrum. Blue peaks at 420 nano meters, green at 530 nano meters, and red at 560 nano meters. From these three colour cell types our brain interpolates all the other colours we perceive. Cyan for example is a pure wavelength of light in the electromagnetic spectrum, but our brain will also interpolate to cyan if our eyes collect a mix of both blue and green (on either side of cyan) wavelength light – if you’re looking at cyan on your screen just now, your brain is faking it out of blue and green pixels :) The most curious colour though is magenta, it’s purely a figment of our minds, no where to be found on the electromagnetic spectrum it exists only when our eyes see a mix of red and blue light. What’s strange is that the brain doesn’t interpolate between red and blue (which would be a green on the spectrum), but maps it to a totally new colour experience.

Who would have thought that the colour magenta only exists in our imaginations!

Visible Colour Spectrum