Interactive Primary Newsletter 34 Nothin' but blue sky....

Light sources Mixing red, green & blue from coloured light sources is an additive process and this can produce all other colours. A computer monitor or the TV screen is made up of lots of tiny dots emitting varying amounts of red, green and blue light. If they are mixed in the right amount we get white light. If red is mixed with green the result is yellow and so on. Fig. 14 shows the projected light from coloured LEDs onto a dark background. Where the coloured discs overlap and all the colours mix, there is an area of white light. Figure 14 - Colour mixing with LEDs - almost white! Anyone wanting to try this particular demonstration should contact Jim Jamieson at SSERC. Black and white