Opticks by Isaac newton

Both Isaac Newton and Johann Wolfgang von Goethe were pioneers in colour theory and philosophy. In Newton's 'Opticks' he observed that a narrow beam of light splits into different bands of colour when passed through a glass prism. He used the word Spectrum in the same study to describe his experiments in colour and optics. Originally Newton divided the Spectrum into 7 colours, Red, Orange, Yellow, Green, Blue, Indigo and Violet, though other philosophers suggest that Indigo is a shade of Blue or Violet as the human eye is quite insensitive to Indigo's frequencies. What I find most interesting is Newton's hypothesise of light being amade up of particles of different colours (corpuscles) and that each colour moves at a different speed so that when light passes through the prism red is moving faster than violet resulting in violet bending more sharply that red creating a spectrum of colours.