What is the colour spectrum?
The modern understanding of colour originated in the discovery of the spectral nature of light by Isaac Newton in the 1600s. Newton considered light to be a stream of particles. His experiments with prisms showed that white light can be split into individual colours. Furthermore, he noted that light of different colours had different refrangibility. Blue light is refracted more than red light, for example, when it passes from air into a medium of higher refractive index such as a prism. We now know that Newton’s famous experiments demonstrated that light consists of energy of different wavelengths. The eye is sensitive to a broad band of wavelengths with the approximate range 350-750 nm. The visible spectrum represents only a small fraction of the full electromagnetic spectrum. Within the visible spectrum certain wavelengths give rise to certain visual sensations. For example, the shorter wavelengths are perceived to be violet and blue. It is important, however, to understand that the
