The colour magenta does not exist anywhere in the spectrum of visible light, and your brain manufactures it on the spot whenever red and blue cones fire togethe... (opens in new tab)

Stare at a rainbow and try to find magenta. It will not be there. The visible spectrum runs from roughly 700 nanometre red at one end to about 380 nanometre violet at the other, with orange, yellow, green, blue and indigo sliding between them in a continuous band first split out by Isaac Newton with […]