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Colour blind

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Generally speaking, about 1 man out of 12 (8%) and 1 woman out of 250 (0.4%) is born colour-blind (clinical term: defective or deficient colour vision). It is the most frequently occurring visual handicap, varying from bothersome to right down hazardous. Ironically, it is also the one least recognised as such, and since it is also an invisible handicap, those afflicted by it will certainly not shout it from the rooftops. That is probably the main reason why this anonymous group is hardly taken into account, except in a negative sense; there still are quite a few jobs that are not accessible to the colourblind. What is not recognized, unfortunately, is that in all the media employed in communication and information presentation, colour may well be one of the most powerful tools for getting the message across. When so many people cannot fully profit from this functional use of colour, this is a problem not only to themselves, but also to those wishing to reach as large a public as possible. For example, the particular colour design used for easy recognition of the Euro paper currency is wasted on the thirteen million colour-blind people in the current Euro zone.
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Inclusive colour design
accommodating the colourblind
Meinard D. Noothoven van Goor, MSc info@blindcolor.com
Director Blind Color, Arnhem
Dr Jan Walraven, janj.walraven@hccnet.nl
Colour consultant, Amersfoort
Dr Johan F.M. Molenbroek,
Assoc Prof Industrial Design Engineering
and
Daan J. van Eijk, MSc, d.j.vaneijk@io.tudelft.nl
Prof Industrial Design Engineering,
Delft University of Technology, Delft
Introduction
Generally speaking, about 1 man out of 12 (8%) and 1 woman out of 250 (0.4%) is born
colour-blind (clinical term: defective or deficient colour vision). It is the most frequently
occurring visual handicap, varying from bothersome to right down hazardous. Ironically,
it is also the one least recognised as such, and since it is also an invisible handicap,
those afflicted by it will certainly not shout it from the rooftops. That is probably the main
reason why this anonymous group is hardly taken into account, except in a negative
sense; there still are quite a few jobs that are not accessible to the colourblind.
What is not recognized, unfortunately, is that in all the media employed in
communication and information presentation, colour may well be one of the most
powerful tools for getting the message across. When so many people cannot fully profit
from this functional use of colour, this is a problem not only to themselves, but also to
those wishing to reach as large a public as possible. For example, the particular colour
design used for easy recognition of the Euro paper currency is wasted on the thirteen
million colour-blind people in the current Euro zone.
Colour deficiency as a handicap
When colours cannot be properly distinguished from one another, this may have serious
consequences. One only has to think of coloured traffic signals, the colour coding of
electricity cables, on/off buttons of machines, coloured pills, stickers on medicine and
toxic substances. And more recently, since the introduction of electronic colour displays,
all kinds of colour-coded information and warning signals on control panels in process
industry and power-plants.
In everyday matters, too, colour blindness may cause much inconvenience and
confusion. Examples are illegible road maps, graphs and tables in study books,
indistinguishable buttons and dials of (parking ticket) dispensers, invisible lines on the
floors of sports facilities, and invisible texts on TV and computer screens. Also, the use
of colour in brochures for advertising and for other information often leaves much to be
desired.
Inclusive design for the colourblind
Whenever colour is used for the coding of information, colour deficiency is typically not
taken into account. Considering that, generally speaking, it is not that difficult to use
colours that the colourblind are able to deal with, this really is a sorry state of affairs. It is
for that reason that Blind Color was founded, an initiative of Meinard Noothoven van
Goor, who, being colour-blind himself, made it his mission to put an end to the needless
discrimination of the colourblind. It is clear that this goal only can be achieved, when all
parties involved in the application of colour for purposes of information coding, are willing
to join the movement of “Design for all”. In this case that means inclusive design that
takes colour deficiency in consideration. This could pose a dilemma to designers,
because they may feel to be less free in the choice of colours. The question they have to
ask themselves, then, is whether they seriously want to take colour-blindness into
account, or simply ignore the needs of 8% of their male customers. Actually the choice
may not be that difficult, since colour-coded information is usually not presented in the
context of artful design. And if it does, there usually is the possibility of double
(redundant) coding like, like for example, in the case of the red traffic light, which is
always positioned at the top.
Inclusive colour design for the colourblind requires a) the appropriate tools for visualising
how colours are seen by colour-blind people, and b) the necessary expertise and skills
for designing “colourblind-proof” solutions. But that is not all, one also has to put colour-
blindness on the agenda of managers in design and, more importantly, managers in
business. Blind Color succeeded in doing so, but it could only do so by first creating
awareness for the subject by publishing a booklet (Walraven, 2003).
Illustrating the problem
Colour deficiency can occur in different forms and degrees of severity ( Pokorny, Smith,
Verriest, Pinckers, 1997), bur rather than going into details, the handicap will here be
illustrated, using pictures created with the TNO colourblindness-simulator. That the latter
really works is shown in Fig. 1, which shows an example of a test picture of the well-
known Ishihara colour vision test.
Figure 1. A test plate of the well-known Ishihara colour vision test (left). The transformed image
on the right shows the test plate as seen through the eyes of a person with a type of colour
deficiency called protanopia.
All of the other pictures, shown below, illustrate in one way or another the loss of
information due to colour-blindness, and hence, the need for the careful selection of
colours when it comes to the functional rather than the aesthetic aspects of colour
design.
Figure 2. Pills as seen in normal (left) and deficient colour vision (right).
Figure 3. Traffic lights as seen in normal (left) and deficient colour vision (right) , respectively.
Note the dangerously located position of the red arrow, which does not comply with the rule “ red
always at the top”.
Figure 4. Two versions of part of a city guide, as seen in normal vision (top left and right) and
deficient colour vision (bottom left an right). The version shown on the left does not take account
of colour-deficient vision. As a result, the built-up areas, ponds, and parts of the road structure
are invisible or nearly so, for those with a colour defect (bottom left).
Figure 5. Two logo’s as seen in normal (left) and deficient colour vision of the type
protanopia.
Figure 6. Euro bills and coins as seen in normal (left) and deficient colour vision of the type
deuteranopia. Note that, due to the similarity in graphics and shapes, the loss of a colour
difference has a relatively high negative effect on the mutual discriminability of the currency.
Figure 7. The layout of the London Tube, as seen in normal (left) and deficient colour vision of the
type protanopia.
The booklet from which the above pictures were reproduced drew quite a response
from the world of trade and business. As a result Blind Colour was asked to provide
solutions for a wide variety of products in which colour plays an important role (e.g.
graphics and markings in schoolbooks, all kind of maps, websites, signposts, banknotes,
control panels, pictograms). This set the scene for raising the issue of colour-blindness
to the level of colour standardisation. The idea was picked up by the Netherlands
Standardisation Institute, resulting in a co-operation that led to provisional guidelines for
colour coding that take colour-blindness into account, i.e. the NPR 7022 “Functional use
of colour – Accommodating people with deficient colour vision” (NEN, 2004).
One of the next endeavours of Blind Colour is to take its mission a step further, by
sharing its expertise with international institutions that are involved in standardisation
(ISO, CEN). But foremost, we shall keep advocating the need for inclusion of the large
anonymous group of people with impaired colour vision, and advice (both solicited and
unsolicited) on how their problems can be alleviated.
Conclusion
Planned activities involved in trying to include the colourblind:
Making the public more aware of the handicap of colour blindness.
Directing the attention of the world of industry, public relations, media and commerce
to this large anonymous group of consumers.
Protecting the interests of the colourblind.
Providing computer-aided screening of coloured lay-outs, so as to aid designers in
using colours that are not confused by the colourblind.
Keeping watch, whether requested or not, on the wrong use of colour, in particular
with regard to material for informative and educative purposes (e.g. maps, text-
books, web sites).
Alerting policy makers in traffic and industry to the dangers of using colours that are
indistinguishable to the colourblind.
Providing information on jobs for which good colour vision is essential, important, or
desirable.
Educating students in Industrial Design Engineering in how to include colourblind
people in their designs. See http://www.io.tudelft.nl.
Advising colour-blind children, their parents and teachers.
Certification of coloured products that have been ‘colour proved’ for the colourblind,
by awarding the registered hallmark “Kleurkeur®” (“Color check”) by Blind Color.
References:
Walraven, J. (2003). Colour-blind, seeing the world though different eyes, Blind Color,
Arnhem, The Netherlands
NEN, Netherlands Standardization Institute (2004). Functional use of colour –
Accommodating people with deficient colour vision”. ( NPR 7022 ) Netherlands
Standardization Institute NEN (in press)
Pokorny, J., Smith, V.C., Verriest, G. and Pinckers, A.J.L.G. (1997). Congenital an
acquired color vision defects. Grune & Stratton, New York.
Acknowledgements
We herewith gratefully acknowledge the funding by the Dutch Ministry of Health
(Directorate Policy for the Disabled), the Dutch Ministry of Social Affairs and the Sikkens
Foundation. Without their support this initative would not have been possible.
Blind Color
P.O. Box 190 T : +00.31.26.443 08 80
6800 AD Arnhem F +00.31.26.443 20 70
The Netherlands E : info@blindcolor.com
Key words: colour-blindness simulation, inclusive design, functional use of colour,
colour standardisation.
Target group: all people that are involved, or have to deal with the functional use of
colour (colour-coding), both at the supplying and at the receiving end.
ResearchGate has not been able to resolve any citations for this publication.
Colour-blind, seeing the world though different eyes, Blind Color, Arnhem, The Netherlands NEN
  • J Walraven
Walraven, J. (2003). Colour-blind, seeing the world though different eyes, Blind Color, Arnhem, The Netherlands NEN, Netherlands Standardization Institute (2004). Functional use of colourAccommodating people with deficient colour vision". ( NPR 7022 ) Netherlands Standardization Institute NEN (in press)
Congenital an acquired color vision defects
  • J Pokorny
  • V C Smith
  • G Verriest
  • A J L G Pinckers
Pokorny, J., Smith, V.C., Verriest, G. and Pinckers, A.J.L.G. (1997). Congenital an acquired color vision defects. Grune & Stratton, New York.