From this standpoint Goethe was able to smile at the Newtonians. He could say that if they persisted in asserting that the colourless, so-called 'white' light is composed of the seven colours of the ordinary spectrum - red, orange, yellow, green, blue, indigo, violet - then they were in duty bound to maintain also that the colourless, 'black' darkness is composed of the seven colours of the inverted spectrum - yellow, orange, red, purple, violet, indigo, blue.