Colourful World

Color or colour (see spelling differences) is the visual perceptual property corresponding in humans to the categories called red, blue, yellow, green and others. Colour derives from the spectrum of light (distribution of light power versus wavelength) interacting in the eye with the spectral sensitivities of the light receptors. Colour categories and physical specifications of colour are also associated with objects or materials based on their physical properties such as light absorption, reflection, or emission spectra. By defining a colour space, colours can be identified numerically by their coordinates.