Colour, is it in the brain?

Colour is a perceptual interaction arising from our ability to discriminate between different wavelengths of light from within a narrow band of electromagnetic radiation. Light itself has no colour. The colour of a specific wavelength can change according to context. For example, in the above picture, despite having the same spectral reflectance, the ‘X’ appears to be different when set against the two different backgrounds (Albers J. 1975). Continue reading