Colour as the human eye perceives it is actually a product of the way light is either absorbed or reflected by objects at the molecular level and how the eye and the brain, working in concert, process this information. This depends on the physical properties of the object. Physically, objects are said to have colour: indeed while some objects reflect light other also emit light themselves. Colour is the visual perceptual property corresponding in humans as the categories red, blue, green — the primary colours — and others. Colour derives from the way white light is broken into its various visible wavelengths, known as the spectrum. These wavelengths interact in the eye with the spectral sensitivities of specialised light receptors within the optic organ. These receptors are known as cone cells.
Because the perception of colour stems from the varying spectral sensitivity of differing types of cone cells in the retina to different parts of the spectrum, colour may be defined and quantified by the degree to which light stimulates these cells. The science of colour is called chromatics, and is the perception of the visible wavelengths of the light, the spectrum, that colours our world. During our lives we become attuned to colour. It is all around us. Colour My World is a collection of stunning photographs taken from around the world, gathered together as a celebration of our colourful planet. In an eloquent way these images provide a visual smorgasbord of vibrant colour — the variety in insects, the subtleness of delicate orchid-flowers, a vivid autumn wood, a Moroccan spice market or indeed a New Guinea tribesman in full ceremonial dress.