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,
Hull Colour Pages and advertisers that it was necessary to split the directory into two separate books, business and residential. "Hull Colour Pages" continued to grow and in 1998 produced the UK's first full-colour business directory, changing the directory's name from "Hull Yellow Pages" to Hull Colour Pages in the process. After a rebrand of Kingston Communications to KC in 2010 the "Hull Colour Pages" was renamed "KC Colour Pages". In 1999 "Hull Colour Pages" launched its Online Directory which, whilst not the UK's first online directory, set the scene for further innovation when, in 2004, "Hull Colour Pages" launched the UK's first