Color blindness is added the majority will say that a match has been achieved. Finally, as yet more red is added, the remaining, protanomalous, observers will declare a match at a point where normal observers will see the mixed light as definitely reddish. Protanopia, deuteranopia, protanomaly, and deuteranomaly are commonly inherited forms of red-green color blindness which affect a substantial portion of the human population. Those affected have difficulty with discriminating red and green hues due to the absence or mutation of the red or green retinal photoreceptors. It is sex-linked: genetic red-green color blindness affects males much more often than females,
Colour trade mark the United States Court of Appeals ruled in 1985 that Owens Corning had the right to prevent competitors from using the colour pink in their insulation products, thus making Owens Corning the first company in the United States to trademark a colour. In 1995, the United States Supreme Court further acknowledged that a colour could be used as a trademark in the case of "Qualitex Co. v. Jacobson Products Co., Inc.", 514 U.S. 159 (1995). The trademark owner must show that the trademark colour has acquired substantial distinctiveness, and the colour indicates source of the goods to which it is