Through experimentation students may discover how a rainbow is formed when sunlight passes through water. A rainbow can be produced if sunlight passes into a tray of water containing a mirror. If the light strikes the mirror at the right angle when it reflects out of the water a rainbow may be projected onto a sheet of white paper. Explain to students that the colour of an object is actually the colour of light that it does not absorb. This means that a red object absorbs all the colours contained in the sunlight except red.
White objects reflect all colours of light.
Black is the absence of colour because a black object is absorbing all colours of light. Remind students that light is a form of energy and energy may also take the form of heat. Experiment by recording the temperatures of different coloured objects such as sheets of coloured paper placed in the sun. Order die results from coolest to hottest. Is there any similarity to the order of colours in the spectrum.