Toronto. For centuries various folk speculated on how we see colour. The postulate of Tom Young hit it on the nail although he had no means to absolutely confirm his theory. In 1802, Young theorized that humans and other primates could see colour because three different kinds of cells in the retina of the eye were turned on each by a distinct and narrow band of colours which the brain transformed into colour. Thus we needed only three colours to see all visible colours. A mix of different strengths transformed into every colour we could see.
We use Red, Green, and Blue. Just look at your TV screen or monitor using a magnifying glass… Modern colour printing – including ink jet – uses a subtractive process of yellow, magenta and cyan plus a later refinement of black to enhance the crispness of the images. One TV maker promotes using a fourth colour – yellow – with their RGB colours to give a more realistic range of visible colours.
Young’s theory was later refined by Hermann von HelmhoItz, another doctor and scientist. It wasn’t until Jim Maxwell did his pivotal experiment with a tartan ribbon, three filters, and three photographic plates in 1861 that Young’s Postulate was confirmed.