The Context - Artificial Human Sensors: Science and Applications - page 44

2.2.2 A “Normal”Colour Scale

The following arguments are intended to raise the question of colour normality
in a population, by showing a frequent variety in the human population. The
colour perception may then exhibit a variation between individuals, that in nor-
mal daily life will not be discovered or create any noticeable problems. However,
there should be a general understanding that a number of people do not perceive
the same colour sensation, in for example, commercial and advertising feature in
a tv program. The quality of colour identification can indeed be increased by cate-
gories of colour deficiency people, that could be supported by an additional artifi-
cial system. A complementary sensor system that compensates and correlates and
strengthens or weakens the colour shades into colours that can be perceived by an
individual's conditions and needs, is considered to very be useful.
A small colour deficiency is present when one or more of the three cones light
sensitive pigments are not quite sensitive and their peak sensitivity is shifted. A
major colour deficiency is present when one or more of the cones light sensitive
pigments is not providing “normal” responses.
Substantial number of people in a population that exhibits a colour deficiency.
It is estimated that between 5% to 8% of male humans and 0.5% of female humans
are born with a colour deficiency. An excellent overview of this subject can be

found in Neitz (2001).
Further, it is shown that one male out of 100 statistically has a colour defi-
ciency (protanomaly) that is prominent under certain hard driving conditions, e.g.,
intense sunlight, rain, or foggy weather conditions, where there is a risk for these
individuals to mistake the colours of a traffic light.
Protanomalous or deuteranomalous colour deficiency individuals can usually
pass as normal participants when taking part in everyday activities. The 5% of
males (deuteranomaly) may make occasional errors in colour names, or may en-
counter difficulties in discriminating small differences in colours, but usually they
perform well. Actually these groups may not even be aware that their colour
perception is in any way different from normal. However, these deficiencies may
affect certain situations, for example, in harsh light conditions.
Dichromasy males normally know they have a colour vision problem. For this
2% of the population, colour deficiency may affect their daily life. They see no
perceptible difference between red, orange, yellow, and green. This group exhibits
a different colour experience compared to the normal viewer, when certain number
of colours appear to be the same colour. The observer actually senses a uniform
view and this deficiency can be effective when determining the status of the traffic
lights when driving in conditions where it is hard to localise the physical position
of the light.
There obviously exists an important and influencial colour deficiency in the
population that simply cannot be ignored when discussing the human perceptual
senses. This wide variety in colour sensations of population is indeed a factor of
importance when pushing forward for a complementary sensing ability that may