Only primates have cones as well as rods in their retinas, so among mammals, only man and the great apes can see colors. 'Primate' also relates to Bishops in the Church of England, and only Bishops are allowed to wear purple shirts. My friend, Lee Rayfield, the Bishop of Swindon and an immunologist, tells me that there are two different shades of purple that are allowed, one bluish and one reddish.
Of course, things are not really colored at all; it is simply the way that light is reflected from their surfaces. Currently we have a vase of purple carnations in our sitting room. In daylight they appear bluish purple, but in artificial light they are definitely a reddish purple.