Accommodating Color Blind Users
Assistive technologies and designing for accessibility have become a common practice in user interface design for most desktop and web-based applications. Guidelines have been in place for over a decade that inform usability professionals how to prepare Web content for users with physical or cognitive disabilities. One of the more common physical disabilities that affects roughly 13% of the general population is color blindness, and its most prevalent form is deuteranopia, or red-green color blindness.
Even as the design community has grown more knowledgeable about human factors engineering, I'm still amazed at how frequently product development teams apply green and red in user interfaces. The traffic light color scheme is a popular metaphor used for desktop window actions and to illustrate scaled levels of severity -- even though these intended meanings don't necessarily translate to the universal cognitive associations of "go", "yield", and "stop". Color is an important design element, but it should never be used as the sole method of communicating information. Secondary elements such as shape, size, location, and contrast can convey information when colors are imperceptible.
The gaming industry has largely ignored color blind users in the past, but the recent efforts of two video game companies are encouraging. 2K Studios is the developer of the award-winning PC and console game franchise BioShock. Primarily a first-person shooter, both BioShock and its sequel BioShock 2, contain mini games that require users to rearrange colored objects in order to solve puzzles. 2K has issued an update for BioShock 2 that adds stripes to the red blocks used in one of its puzzles -- an example of texture and contrast as secondary design elements.
Helsing's Fire is a popular puzzle game for Apple's iOS devices, but players are required to use vibrant red and green-colored potion bottles that have little physical distinction. The game's developer, Ratloop, issued a downloadable update that adds a "color blind adjustment" toggle to the settings. When activated, green bottles become white and there is greater contrast between the red and blue colors. These subtle changes greatly enhance the game play experience for color blind users and help promote the importance of accessibility in software design.
