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 recovery to remove this interference, these patterns are retained even in the existing monochrome film prints and theoretically contain the original colour information. (Occasionally the colour information was filtered out using a notch filter and is lost.) The idea to recover this information was originally suggested by BBC researcher James Insell. In practice however, the recovery of this colour information from telerecordings is highly complex for several reasons. Firstly, the colour reference timing signal, known as the "colour burst," is absent from telerecordings, as it is nominally off the edge of the visible screen area being recorded. This timing has to