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 cast Colour cast A colour cast is a tint of a particular colour, usually unwanted, which affects the whole, or portion, of a photographic image evenly. Certain types of light can cause film and digital cameras to have a colour cast. Illuminating a subject with light sources of different colour temperatures will usually cause colour cast problems in the shadows. In general, the human eye does not notice the unnatural colour, because our eyes and brains adjust and compensate for different types of light in ways that cameras cannot. In film, colour casts can also be caused by problems in development.