Things appear coloured to an observer because colour corresponds with a property of light that is visible to the human eye. The visual experience of colour is associated with words such as red, blue, yellow, etc.
- The colour an observer sees depends on:
- The range and intensity of wavelengths of visible light emitted by a light source.
- The path that the light takes and the different media and materials it encounters on its journey from its source to the retina of a human eye.
- Optical phenomena such as absorption, dispersion, diffraction, polarization, reflection, refraction, scattering and transmission.
- Predispositions of an observer such as their personal and social experience and cultural context.