Light and Colour
Colour is a phenomenon of light, and a visual perception using the physical sense of human sight. Light is one of the four essential elements in the visual experience of colour. The four essential elements are: a coloured object; a light source to illuminate the coloured object; the human eye as a receptor of the light energy reflected from the object; and the human brain to interpret the electrochemical neural impulses sent from the eye. Visible light radiating from the sun consists of a broad spectrum of wavelengths ranging from violet to red. Display devices mix red, green, and blue light to form different coloured pixels in an image. The characteristics of a material and the incident light striking them determine the apparent colour of an object. The chapter presents experimental work that demonstrates mixing coloured light to produce different colours. Isaac Newton’s colour wheel and black and white colour wheels are used in the experiment.