Waves can be measured in terms of wavelength, frequency and amplitude. A wave with greater amplitude carries more energy and will be a brighter light. As all light waves travel at the same speed, a long wavelength will have a lower frequency. If white light passes through a transparent object, such as a raindrop, lens, prism or a thin film of oil, it can split into its constituent colours. If white light strikes a coloured surface, the surface reflects a proportion of the light and absorbs some wavelengths and so an an object appears to be a certain colour.
Colour filters filter out certain colours in white light and transmit certain others.
Reflection All objects reflect light to a certain extent. The eyes are sensitive to the light reflected from objects. Curved mirrors produce different images. From further away the image appears smaller and upside down. Refraction Light travelling from one medium to another appears to bend - a medium being any transparent object, eg air, water, glass, plastic.