Aristotle believed that there were actually only three colours present in the rainbow, : of these, the first is produced by the dulling of white light when it is reflected in or obscured by a dark medium such as smoke, cloud, or water, and exemplified in the redness of the sun as seen through haze around the horizon. Successive failures of sight weaken the colour further, first to πράσινov and then to άλoυργóν. Between the first two colours a fourth, ξανθóν, is often apparent, being the result of the juxtaposition of the two colours. This last statement, where it has not been ignored as one of the inexplicable or misguided things Aristotle says from time to time, has met with considerable criticism