Colour Mixer may be shown using this apparatus. Colour mixing takes place when two or more colours come together to form a different colour. This apparatus demonstrates how different colours of light form - from the three primary colours. The three basic colours for mixing light are red, green & blue. There is a control box which controls the intensity of six numbers of LEDs (diodes) which are mounted on a stand. Additive and subtracting colour mixing are demonstrated on the screen.