English

About this document
This document is based on material issued by the Color Universal Design Organization (CUDO), a
nonprofit organization, with some additions and revisions made under the supervision of CUDO.
For the information about CUDO and the material, see the following web sites:
http://www.cudo.jp

Contact
If you have any question about this handbook, please get in touch with Color Universal Design
Organization.
CUDO Office

Minato-ku Kita-aoyama 2-11-10-202
Tokyo 107-0061, Japan
phone: (81) 3-5775-5420
fax: (81) 3-5775-5430
E-mail: info@cudo.jp
URL: http://www.cudo.jp
General Manager : Tanaka, Yosuke

Copyright© 2006 Color Universal Design Organization
Copyright© 2006 EIZO NANAO CORPORATION
No part of this document may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means,electronic, mechanical, or otherwise, without the prior written permission of Color Universal Design Organization and
EIZO NANAO CORPORATION.
Color Universal Design Organization and EIZO NANAO CORPORATION are under no obligation to hold any submitted
material or information confidential unless prior arrangements are made pursuant to Color Universal Design Organizationand EIZO NANAO CORPORATION's receipt of said information.
EIZO is a registered trademark of EIZO NANAO CORPORATION in Japan and other countries.

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TABLE OF CONTENTS
About this document............................................................................................2
Contact ...............................................................................................................2

1. What is Color Universal Design?.......................................................... 4
3 (+1) Principles ...................................................................................................4
Who is it for? .......................................................................................................5

2. How to put Color Universal Design in practice................................... 6
Why is Color Universal Design so important now?..............................................6
Valuable to everyone regardless of which color vision type .................................7“Color Barrier-free” – The trend of the times ......................................................7
Effective cases of Color Universal Design.............................................................8

3. What is colorblindness? ....................................................................... 9
Color vision mechanism and different types of colorblindness.............................9
Notes on use of simulations ...............................................................................11
Why simulations must be checked by colorblind people ....................................12

TABLE OF CONTENTS

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English

1. What is Color Universal Design?
People see color with significant variations. In Japan, there are more than 5 million
people in total who see color differently from ordinary people, due to their genetic types
or eye diseases. Color Universal Design is a user-oriented design system, which has beendeveloped in consideration of people with various types of color vision, to allow
information to be accurately conveyed to as many individuals as possible.

3 (+1) Principles

4

1

Choose color schemes that can be easily identified by people with all types of color
vision, in consideration with the actual lighting conditions and usage environment.

2

Use not only different colors but also a combination of different shapes, positions,line types and coloring patterns, to ensure that information is conveyed to all users
including those who cannot distinguish differences in color.

3

Clearly state color names where users are expected to use color names incommunication.

+1

Moreover, aim for visually friendly and beautiful designs.

1. What is Color Universal Design?

English

Who is it for?
So-called “colorblind people” (also known as Daltonian, color-weak people, or people
with color-vision defects, color-vision deficiencies, or dyschromatopsia) account for thelargest proportion of those who have different color vision from ordinary people. In
Europe and the US, one out of every 10-12 males and 200 females is believed to becolorblind1, with a total of over 10 million in the US and around 2 million in the UK. In
Japan, one out of every 20 males and 500 females is believed to be colorblind with a
total of over 3 million nationwide2. And globally, more than 200 million people are
believed to be colorblind, and this figure is equivalent of the number of males with type
AB blood1. Colorblind people have normal eyesight (resolving power of the eye) and
can also see small objects clearly. For some particular combinations of colors, however,they have different vision from the common-type vision (see the following picture andalso page 9 for details).

In addition, there are several tens of thousands of people who cannot distinguish any
colors and can tell differences in color only by their brightness or darkness. Most ofthese people also have weakened eyesight.
Age-related illnesses such as glaucoma and cataract can affect how we see color as oureyesight weakens. In Japan, there are over 1.4 million cataract patients in total andapproximately 5.6% of the population aged 65 or older suffer from the disease. As
society ages, the number of such patients tends to increase. Furthermore, diseases suchas diabetic retinopathy and retinitis pigmentosa can also weaken eyesight. A total ofseveral hundreds of thousands of people are so-called “people with low vision3, withcorrected vision of 0.05 or more and below 0.3 in both eyes, who require consideration
for not only their weakened eyesight but also simulated views and degrees of contrast.

1

Reimchen, T.E. (1987) Human Color Vision Deficiencies and Atmospheric Twilight. Soc Biol, 34, 1-11
Ota, Y. and Shimizu, K. (1999) Shikikaku to Shikikaku Ijou [Normal and Defective Color Vision]. Tokyo. KaneharaCo., Ltd.
3
Based on the World Health Organization (WHO) definitions.
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1. What is Color Universal Design?

5English

2. How to put Color Universal Designin practice
Why is Color Universal Design so important now?
In 21st century society, use of color is increasingly becoming an important means of
information transmission. Several years ago, for example, black and white printing was
the norm for newspapers, magazines, textbooks and general publications. But recent
development of color printing technology has dramatically turned them into color.
These days, even simple guide maps would look rather inadequate unless they were incolor. Color has also been introduced to the operation screens of photocopiers, ormobile phones, automatic ticket-vending machines, automatic teller machines (ATMs),
etc., and most such screens are now in color. The use of a variety of colors has also
become the standard for electronic information boards. Electronic devices and homeelectric appliances used to have pilot lights with a simple on/off function, but they now
commonly come with new types of lights which illuminate in a number of colors toconvey information in various different ways. Color-coding is in place in public
facilities, museums, exhibition sites, etc., where rooms and areas are divided according
to theme colors and full of colorful information displays. At railway stations, train lines
are color-coded for direction purposes; route maps and time tables are illustrated withlines and characters in a variety of colors.
As described above, there are so many more scenarios where color is a tool for
conveying information, compared with one or two decades ago. However, many color
displays are still designed with only common-type color vision in mind. As a result,
there are more and more cases like the charging adapter shown in the photographbelow, where the information provided is difficult for colorblind people to read,
resulting in inconvenience to them. In our current society, life is ironically becoming
even harder for the colorblind.
Color Universal Design has been developed to resolve this major issue. Giving
consideration to Color Universal Design allows you to use color effectively and create
colorful designs that everyone will think beautiful, while still conveying information
accurately.

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2. How to put Color Universal Design in practiceEnglish

Valuable to everyone regardless of which color vision type
Color Universal Design is not a “peculiar design concept developed only for somecolorblind people and rather difficult for people with common-type color vision to see”.
The purpose of designing with the colorblind in mind is to completely reexamine theexisting inconsistent color-designing procedure that tends to increase the number ofcolors unnecessarily, establish an order of priority for information elements to beconveyed, and create designs that take into account the impressions and psychologicaleffects they may give to the receiver of the information. Color Universal Design isfocused on ease of use from the user’s perspective, rather than only relying on thedesigner’s aesthetic sense and sensitivity. This will result in “well organized easy-to-see
designs” for people with the common-type color vision as well. Therefore, Color
Universal Design is valuable not only to the colorblind but also to everyone.

“Color Barrier-free” – The trend of the times
Thoughtful use of color to ensure that the colorblind are not disadvantaged is called a“color barrier-free” presentation. Until recently, vision-related barrier-free activities were
designed only in consideration of people who can hardly see. However, the importanceof color barrier-free presentations is becoming increasingly recognized at a rapid pace.
For example, both Section 508 of the Rehabilitation Act in the US, enacted in 1998, andPhase III of the Disability Discrimination Act in the UK, started from 2004, explicitly
call for the consideration to people with disabilities including the colorblind among
others.

2. How to put Color Universal Design in practice7

EnglishEffective cases of Color Universal Design8

Public facilities

At public facilities such as hospitals and government offices,
careful thought must be given to floor directories and warning
signs, color schemes for application forms, electric displays inreception areas, color-coding for items to be handed over to theuser of the facilities such as medicines, etc. At hospitals, inparticular, extreme care must be taken as they are frequented byold people as well as eye patients.

Museums & exhibitionsites

In addition to the above, attention must be paid to how to makedescriptions of exhibits easy to understand.

Railway stations & airports

Consideration must be given to route maps and directional signs
on platforms, electronic information boards to indicate departures
and arrivals, etc.

Roads

Attention must be paid to road signs and color tones of lines
painted on roads, electronic information boards that indicate roadinformation such as traffic congestion, etc.

Schools & prep schools

Consideration must be given to the colors of chalk and marker
pens, the selection of teaching materials, etc.

Newspapers, magazines,
text books, reference
books, operation manuals,
PR magazines for local
governments & companies

Careful thought must be given to font coloration, color schemes,line types and color-coding within descriptive figures and graphs,
legend indication methods, etc.

Maps, route maps, guidemaps, car navigation
devices & globes

Attention must be paid to color schemes for color codes, line
shapes, legend indication methods, etc.

Ticket-vending machines& ATMsConsideration must be given to color schemes and designs ofoperation screens.

Electronic devices

Careful thought must be given to color schemes for charging
lights in mobile phones and digital cameras as well as designs fortheir display screens.

Electronic officeequipment

Consideration must be given to operation indicator lights andoperation screens of photocopiers, fax machines, PCs, etc.

Home appliances

Consideration must be given to operation indicator lights ofelectric rice cookers, electric kettles, microwave ovens, etc.

Audiovisual equipment

Careful thought must be given to operation indicator lights andoperation screens of TVs, VCRs, etc.

Cars

Consideration must be given to display colors on meters and todesigns of operation panels.

Medicines

Attention must be paid to color-coded displays of medicine typeand dose, particularly for those prescribed at hospitals andpharmacies.

Stationary

Consideration must be given to color schemes for color-codedfiling products such as document folders and binders, ink colors ofball-pointed pens, as well as how to make it easier to distinguish
one color tone from another for the colors used in 8 and 12 color
sets of marker pens, colored pencils, crayons, paints, etc. The
correct color name should also be clearly shown on each item.

Websites

Careful thought must be given to font coloration, color schemes
for descriptive figures, and also the selection of background color.

PC software

Attention must be paid to how to display each type of screen.

2. How to put Color Universal Design in practiceEnglish

3. What is colorblindness?
Color vision mechanism and different types of colorblindness
The human retina has two types of photoreceptor cells: rod cells that only work in
darkness, and cone cells that only work in light. Cone cells are further divided into threegroups depending on which wavelength of light they mainly detect (spectral sensitivity):
L (red), M (green) and S (blue).

People with the common-type color vision have all of three types of cone cell. In
Europe and the US, approximately 90-92% of males and over 99% of females areclassified in this category. People with protanopia (protanopes) can be divided into twogroups: those who don’t have L cone cells that mainly detect red light (strong
protanopia) among the three types of cone cells; and those who have L cone cells with
their spectral sensitivity shifted more toward M cone cells (weak protanopia). As
shown in the following figure, people with strong protanopia have a vision significantly
different from the common-type vision, while those with weak protanopia have theirvision somewhere between the two vision types. Similarly, people with deuteranopia(deuteranopes) can be divided into two groups: those who don’t have M cone cells thatmainly detect green light (strong deuteranopia); and those who have M cone cells with
their spectral sensitivity shifted more toward L cone cells (weak deuteranopia). Most
colorblind people belong to the above four types (strong protanopia, weak protanopia,
strong deuteranopia and weak deuteranopia), and about 8-10% of the total malepopulation of Europe and the US belong to one of them (5% of males in Japan, 2-4% in
Africa).

3. What is colorblindness?

9EnglishPeople who don’t have S cone cells that mainly detect blue light have the color visioncalled tritanopia (tritanopes). Those who have only one type of cone cell, or have nocone cells at all but only rod cells, have the color vision called achromatopia(achromats). They can only detect differences in color by its lightness or darkness. Less
than one out of every 100,000 people are tritanope and about the same number ofpeople are achromatope. While there is no difference in the percentage of tritanopes andachromatopes between men and women, more males have protanopia or deuteranopia
than females, with only one out of several hundred women. This is because theprotanopia and deuteranopia genes are both on the X chromosome.
Apart from the seven types of vision over the five categories described above, color
vision is also affected by eye-related illnesses. A cataract is an eye disease that causes
the crystalline lenses to become white and cloudy. When the degree of cloudiness isextreme, the lenses do not allow blue to green light of short wavelength to pass through.
Furthermore, images become blurry due to the dispersion of light. Glaucoma, diabetic
retinopathy and retinitis pigmentosa are diseases that decrease the number ofphotoreceptor cells in the retina, weakening the eyesight. Weakening eyesight has themost significant effect on the S cone cells, which are the least common of all the three
types of cone cell. As a result, the people affected have color vision closer to tritanopia.
The severity of these eye diseases differs significantly among the patients. Also, some
affect mainly the center of their view, while others mainly the edges. Therefore, one of
the characteristics of such eye diseases is significant individual variation, which makes
stereotyped simulation difficult.

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3. What is colorblindness?

EnglishNotes on use of simulations
Several types of simulation software have been launched to simulate the views
experienced by some colorblind people, as shown on pages 5, 6 and 9. Such software
can be used to process photographs of products or facilities so as to allow people with
common-type color vision to simulate the vision of the colorblind. The simulation
applications are highly effective tools for identifying existing problematic color schemes
to create new designs. Our system is built on hardware-based simulations that allow theuser to control colors displayed on the monitor using the computer. Therefore, it isdifferent from competitors’ products, which need to convert images one by one by using
software. With our product, the user can convert and view all of the images displayedon the monitor, even movies, in real time.
The user, however, must take note of the following points when viewing images
converted through the simulation process.
(1) In the simulation of protanopes and deuteranopes, the vision of the most strongly
affected people is reproduced. Approximately one third of colorblind people are
estimated to be in this category. The remaining two thirds have their color visionsomewhere between that and the common-type color vision, including those whohave their vision very similar to the common-type vision. For this reason, please takecare not to believe that all colorblind people, including those more weakly affected,
have color vision as indicated in the converted images.
(2) When there is a color that is difficult to distinguish, people judge it by using
information other than the actual color as a complement. For example, we view anapple as red and paper as white, even when both are lit in red under a red light. The
same applies to colorblind people. For them, it is difficult to distinguish some tonesof sky blue from some tones of pink. In this case, colorblind people view that theclothes worn by a man should be sky blue (even if pink), and those worn by awoman pink (even if sky blue). This happens because people judge colors bycomparing them with their memories and experiences - men often wear sky blue
while women wear pink.
In a color vision simulation, a range of colors that are difficult for colorblind people
to distinguish are all converted into one color, which is determined by a calculation
formula of the colorblind theory. Therefore, the color displayed is not necessarily
the color recognized by colorblind people. For example, pink and sky blue, as
described above, both appear as sky blue in simulations, but it is incorrect to thinkthat “colorblind people see pink as sky blue”.
Simulations do not show you “which color colorblind people see as a certain color”.
Therefore, they should only be used to understand “which colors on the screen are
difficult for them to judge”.

3. What is colorblindness?

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Why simulations must be checked by colorblind people
Simulations are effective but not perfect. First, they have limitations such as the inability
to reproduce the complete vision of a colorblind person. The color of light-emitting
objects such as LEDs cannot be reproduced as the correct color, since these color are
beyond the color range that can be handled on digital camera or computer screens. This
also results in inaccurate simulations.
In addition, even when some colors are viewed as similar by people with common-type
color vision, they may be viewed as completely different by colorblind people.
Colorblind people are more sensitive about levels of brightness and saturation thanthose with the common-type vision, even for the slightest difference. For this reason,some colorblind people may become confused by a slight difference in color that cannot
be noticed by people with the common-type vision. Conversely, even when people with
common-type vision expect some color scheme to be difficult for colorblind people toview, it may be in fact rather easy for them to distinguish. Therefore, people with
common-type color vision cannot perceive how colorblind people exactly see, simply bylooking at simulated images on the screen.
Furthermore, colors of the products and displays are also significantly affected bylighting. Therefore, it is very important to evaluate the visibility, readability and design
quality of each product or display not on the computer screen, but under the samelighting conditions as for the site at which the product or display will actually be used.
Color Universal Design is a creative process consisting not only of adjusting colors, butalso of working out how to use different shapes, line types and coloring patterns andcreating designs in a comprehensive manner by using characters and color names
without spoiling the beauty of the designs. Neither the beautiful balance of color noreasy-to-see designs can be achieved if the designer simply chooses a confusing color on
the computer and simply replace it with a different color.
For this reason, in order to achieve Color Universal Design, it is essential for thedesigner to work together with colorblind people through discussions to carry out
checks and produce ideas. You should however remember that there are different typesof color vision, e.g. color is viewed very differently between protanopia anddeuteranopia. The same color use may be completely easy for protanopes but extremely
difficult for deuteranopes to see, or vice versa. Therefore, it is important during thechecking process to verify designs not only with the common-type color vision but also
for all four major types of colorblindness (strong protanopia, weak protanopia, strong
deuteranopia and weak deuteranopia), rather than selecting only one of them. This gives
five types of color vision to be included in the verification process.

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3. What is colorblindness?