"Colour" and "color", "favourite" and "favorite", "honour" and "honor"...Have you ever wondered why Americans spell those words without a "u"?

Colour saturation: Change the color saturation of your image.

His 1939 patent for color TV receiver circuitry was extended until 1971 because for most of the patent 's normal life there was no colour TV to receive and thus no hope of reward for the invention.