UPSC 2013 CDS 2 GK Paper

A ray of white light strikes the surface of an object. If all the colours are reflected the surface would appear white. An object has the colour of the wavelengths that it reflects. A material that reflects allwavelengths of visible light appears white. If all the colors of white light are absorbed by an object, without reflecting any colour then such object appears black. For example, a black board appears black, because it absorbs all the colours of light falling on it.