art-and-sterf:
Colour-blindness is not exactly something high on an artist’s list of things to consider, so you might be wondering why it’s important at all. The simple answer is, your audience. Color blindness, colour vision deficiency, or CVD, affects approximately 1 in 12 dmab (8%), and 1 in 200 dfab people in the world.
While you as an artist may have Trichromacy (full color vision), if you end up with a color blind client, or even if you are just designing something for a public audience, knowing what color blindness is and how it affects the way other people view your work is important.
Four Types Of Color Blindness
Protanopia is a severe type of color vision deficiency caused by the complete absence of red retinal photoreceptors.
Those affected have difficulties distinguishing between blue and green colors and also between red and green colors. It is a form of dichromatism in which the subject can only perceive light wavelengths from 400 to 650 nm, instead of the usual 700 nm.
Pure reds cannot be seen, instead appearing black; purple colors cannot be distinguished from blues; more orange-tinted reds may appear as very dim yellows, and all orange–yellow–green shades of too long a wavelength to stimulate the blue receptors appear as a similar yellow hue.
Protanopes are more likely to confuse:
Black with many shades of red
Dark brown with dark green, dark orange and dark red
Some blues with some reds, purples and dark pinks
Mid-greens with some oranges
Deuteranopia is a type of color vision deficiency where the green photoreceptors are absent.
It affects hue discrimination in the same way as protanopia, but without the dimming effect.
Deuteranopes are more likely to confuse:
Mid-reds with mid-greens
Blue-greens with grey and mid-pinks
Bright greens with yellows
Pale pinks with light grey
Mid-reds with mid-brown
Light blues with lilac
Lacking the short-wavelength cones, those affected see short-wavelength colors (blue, indigo and a spectral violet) greenish and drastically dimmed, some of these colors even appear as black.
Yellow is indistinguishable from pink, and purple colors are perceived as various shades of red.
Tritanopes are more likely to confuse:
Light blues with greys
Dark purples with black
Mid-greens with blues
Oranges with reds
People with monochromatic vision can see no colour at all and their world consists of different shades of grey ranging from black to white, rather like only seeing the world on an old black and white television set. Achromatopsia is extremely rare, occurring only in approximately 1 person in 33,000 and its symptoms can make life very difficult. Usually someone with achromatopsia will need to wear dark glasses inside in normal light conditions.
In cerebral achromatopsia, a person cannot perceive colors even though the eyes are capable of distinguishing them. Some sources do not consider these to be true color blindness, because the failure is of perception, not of vision. They are forms of visual agnosia.
Color Spectrum Comparisons
Checking Your Work In Photoshop
Photoshop has a feature for viewing your work in Protanopia and Deuteranopia colour blindness filters.
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