Minium (pigment) Minium (pigment) Minium, also known as red lead, is a bright orange red pigment that was widely used in the Middle Ages for the decoration of manuscripts and for painting. It was made by roasting white lead pigment in the air; the white lead would gradually turn yellow, then into an orange lead tetroxide. The color varied depending upon how long the mineral was roasted. During the Roman Empire, the term minium could refer either to the pigment made from ground cinnabar or to the less expensive red lead. The name came from the river Minius in Iberia (now forming
Evolution of human colour vision allow them to see a wider range of the electromagnetic spectrum. Secondly, new random connections would create wavelength opponency and the new wavelength opponent neurons would be much more sensitive than the non-wavelength opponent neurons.This is the result of some wavelength distributions favouring excitation instead of inhibition. Both excitation and inhibition would be features of a neural substrate during the formation of a second pigment. Overall, the advantage gained from increased sensitivity with wavelength opponency would open up opportunities for future exploitation by mutations and even further improvement. Evolution of human colour vision Evolution of human colour vision over time: