It has been understood since Isaac Newton's time that colour has no independent existence in the physical world. (1)----, colour is constructed by the brain out of combinations of different wavelengths of otherwise colourless light. Colour perception is an elegant mechanism (2)---- the brain keep track of surfaces consistently even as lighting conditions change. Human beings, moreover, can detect only a narrow band of the broader electromagnetic spectrum, stretching (3)---- the lower range of infrared and the upper range of ultraviolet. Every colour we (4)----, every element of a person's visual experience, arises from this narrow slice of physical reality. (5)---- this, it becomes clear that sensory experience can never be a complete representation of an external, objective world; it is simultaneously less than that and more than that.