Colorblindness – A Usability Guide for Commercial Applications, Part 2

Colorblind people represent a significant but often neglected talent pool and consumer segment. Ten percent of Caucasian American men but less than one percent of women are estimated to have some form of colorblindness. Identifying opportunities to make products usable by as many people as possible, without degrading overall quality or performance, is a quality assurance function that is not always well understood or practiced.

Part 1 of this two-part series looks at increasing the usability of products and the communication of information. The second part of this guide concludes with an example of potential impacts if colorblindness is ignored.

The Trouble With Blue

The use of blue fonts is widespread, particularly online, where links to other Web pages are usually rendered in blue. Fonts in light shades of blue have the effect of reducing background contrast. The lighter the font, the harder it is for colorblind people to read.

Even subtle changes in blue can have major impacts on the levels of eye strain experienced by even moderately colorblind people. The landing pages of Craigslist.org, for example, are rendered almost entirely in light blue.

Yahoo’s online e-mail service relies heavily on blue fonts. However, these fonts are a little darker and often bolder than the blue fonts on Craigslist, making Yahoo more attractive and easier to use.

Displaying Icons

Contrast issues extend to program icons, which are designed with the intention of making them stand out — especially when used in program start menus, system trays, quick launch bars, desktops and other environments where easily recognized icons may enjoy higher click rates than ones that are difficult to distinguish from background colors.

The reliance on blue backgrounds in graphical user interfaces (GUIs) creates challenges for icon designers who seek to use blue in their icon designs. Blue is the default color scheme in Windows XP and is a popular color scheme in GNU/Linux desktop distributions.

The following program icons fail the test of being easily recognizable by colorblind people using blue color schemes: Google Talk, RealPlayer, Skype (except in the system tray), Microsoft Windows Internet Explorer browser and Microsoft Windows Live Messenger. The Firefox browser icon barely earns a passing grade in blue color schemes. Firefox and Google Talk icons perform better in silver desktop color schemes than in blue schemes, but most other icons do not.

HP’s program icons often rely on blue, but contain sufficient white space to make them easily recognizable. The program icon for the Opera browser earns high marks for using a dark, high contrast color scheme and for its simple, uncluttered design.

The program icon for Yahoo Messenger is modestly successful because its yellow color contrasts with blue and silver GUI backgrounds. Colorblindness rarely presents everything as completely monochromatic. Even severely colorblind people can almost always distinguish yellow from blue.

The recognizability of the Yahoo Messenger program icon is bolstered by including dark colors to set off the eyes and mouth. One characteristic of colorblind people, as illustrated here, is that they are not able to communicate colors accurately. Everything might be articulated as being within a range of “brown” or “blue” or “dark.”

Distinguishing colors and naming colors are separate tasks, with colorblind people being better at the first task than the second. To ask colorblind people to precisely identify a color is often seen as a nonsensical question. Because it is.

Components That Contribute to Poor Usability

The icons for Microsoft’s Windows Live Messenger chat program provide lessons in the components that contribute to poor usability. The use of red or green within the program icon itself makes the icon difficult for mildly colorblind people to spot. The icons within the chat program’s main user interface rely solely on colors to distinguish other users (called contacts) that are online from contacts that are not.

The workaround for colorblind users is to reset the display so as to organize their contacts according to positions that can be memorized, with contacts that are online appearing in groups separate from offline contacts. However, this reduces the features that are available to other users who can organize their contact lists in groups such as friends, work contacts, and relatives.

MySpace member pages often provide dramatic examples of poor usability. Here the use of text on top of photos and on top of other poorly contrasting backgrounds can produce pages that are decipherable only to those with full-color vision.

In the case of MySpace, it is the individual consumer who is responsible for their own color selections and for the accessibility of their personal Web pages. In other social networking sites, it is the site operator who bears responsibility for overall usability.

Turning back to Microsoft, their competing service to MySpace is called Windows Live Spaces. It is a great offering (try it!) unless you happen to be colorblind. There is such a thing as trying to be too clever, and Live Spaces achieves this in both its initial sign-up process and in the default home page settings through an elaborate low-contrast user interface that is one of the most difficult GUIs for colorblind people today.

When I see companies that I respect and admire using quality assurance processes that fail to correct obvious usability flaws, it causes me to wonder about the integrity of quality assurance processes throughout those organizations.

When conducting quality assurance activities, there is no substitute for usability tests with people who are actually colorblind. Grayscaling out a screen grab does not enable a non-colorblind person to see what a colorblind person is seeing.

An hour or two of training to help designers avoid mistakes is cheaper than creating mistakes and then having to go back and fix them. The size and significance of the colorblind demographic justifies this level of effort.

Accessibility and Boredom

To have all product GUIs designed for colorblind people would be boring. Instead, developers can create a default GUI that is accessible for both colorblind and noncolorblind users, but then allow users to select alternate color schemes that are consistent with personal preferences and visual capabilities.

The Microsoft Windows XP operating system provides a good example. Microsoft allows users of its Windows XP operating system to select from among three color schemes: blue, silver and green. The default display is the blue color scheme, which is both accessible and pleasant for the vast majority of colorblind users.

The biggest problems caused by the implementation of that color scheme are caused by Microsoft’s own icons, which fail to take into account the usability principles described above. As a case in point, the browser program icon for Windows Internet Explorer is also blue. It is hard for colorblind users to recognize that icon when it appears with a blue background.

Developers could select colors for program icons that maximize their visibility when used with the default color schemes of different operating systems. During program installation, the operating system could be recognized and icon colors and other program colors chosen accordingly.

Hardware Coloring Could be Dangerous

In electrical hardware, the use of red and green color coding to distinguish electrical wires is unnecessary and dangerous. Other ways of marking wires include striping, dashes, and circles. Some hardware is more dangerous and sensitive than others. Nuclear weapons provide a good example.

The morning after high school graduation, as a fresh-faced 17-year-old, I went off to the U.S. Army and its Special Weapons Training Center in Texas. Working on training versions of nuclear warheads, I was pulled out of class one day for having performance difficulties and sent to a clinic to have my eyes checked for colorblindness. Failing a colorblind test would have resulted in reassignment to cooks’ school.

The clinic was attached to an armored cavalry unit. Inside was a physician more interested in flirting with the nurses than giving tests for colorblindness. To make it quick, he asked me to name the colors of a couple items in the clinic. I guessed correctly and was sent merrily back to wiring up atomic and conventional high-explosive warheads with a paper certifying that no colorblindness existed.

Later, when working on warheads in the field, I made sure that there was always someone nearby who could tell me the colors of the wires. The wires could then be distinguished by memorizing their positions. But with so many wires …

There are restrictions against colorblind people holding certain positions in our society, but colorblind people sometimes get around those restrictions. Low and no-cost common-sense modifications can be made, and should be made, to reduce the impacts on society from a minor handicap that is often no more than a fashion inconvenience for those afflicted with it. The alternative, as in the case of nuclear weapons, is often unthinkable.

Now let’s fix those traffic lights.Colorblindness – A Usability Guide for Commercial Applications, Part 1