Colour and Light

Is there more to light than meets the eye? Does a green filter change white light into green light? What colour of light is observed when blue and yellow filters are mixed? The answers to these questions may surprise your students. This demonstration uses a holographic diffraction grating and an overhead projector to produce a very large, very sharp rainbow of colour. The large spectrum allows you to demonstrate the true nature of colour and light and address common misconceptions related to the perception of colour.