1 Cover the first torch with the red square of cellophane and fix with an elastic band. 2 Cover the second torch with the square of green cellophane and also secure with an elastic band. Shine the torches at the same point on the white wall. You have just mixed different coloured light! When you shine the torches at the same point on the white wall, you will notice that the spot of light is yellow. You have proved that yellow light is made up of green and red light. Light’s primary colours are red, green and blue. By mixing the primary colours you get yellow, cyan and magenta. The colours you make when you mix paints are different to the colours that result from mixing light. Why don’t you repeat the experiment with three torches and a sheet of blue cellophane? What do you notice now?

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