ABSTRACT
The ability of animals to perceive colour varies greatly from species to species. Nocturnally active mammals tend to have poor colour discrimination, because their visual systems relymainly on rods for light detection. The majority of mammals active during daytime are dichromatic, meaning that they have only two cone pigments, one with a response peak in the yellow-to-green part of the spectrum and the other in the blue-to-violet range. Consequently their colour discrimination is probably similar to that of people with the commonest form of colour blindness. Waving yellow rags at bulls might be more provocative and dangerous than waving red ones, because yellow light is closer to the peak sensitivity of the commonest cones. In a china shop, though, such animals should be able to discriminate between cheap terracotta flower vases and expensive Wedgwood Blue Jasper ware.
