Does anyone know the history of using Red / Green for signalling? (Colour Blindness question.)?

Well,the signaling system is based on the refractive index of the colors.When light pes through one side of a prism,a spectrum is formed.Red on the top then orange,yellow,green etc.....red can be seen from a far distance than yellow and green.So red is placed on the top, yellow in the middle and green in the bottom......very few people really interested in such type of questions. "Visible light" corresponds to a wavelength range of 400-700 nanometers and a color range of violet through red.The visible colors from shortest to longest wavelength are violet,blue,green,yellow,orange and red.Yellow is natural color(sunlight). Red and orange are similar so two colors i.e.red and green with highest wavelength are used in any signaling system.