ACE: a color expert system for user interface design

Color is used in computer graphics to code information, to call attention to items, to signal a user, and to enhance display aesthetics, but using color effectively and tastefully is often beyond the abilities of application programmers because the study of color crosses many disciplines, and many aspects, such as human color vision, are not completely understood. We compiled a comprehensive set of guidelines for the proper use of color, but even these guidelines cannot provide all of the aesthetic and human factors knowledge necessary for making good color selections. Furthermore, programmers may misinterpret or ignore the guidelines. To alleviate some of these problems, we have implemented ACE, A Color Expert system which embodies the color rules and applies them to user interface design. The goal of the implementation was to test whether an automated mechanism would be a viable solution to the problem of choosing effective and tasteful colors.Our implementation is written in OPS5, a production system programming language, which allowed us encode rules in a similar fashion to our existing set of guidelines. ACE takes a user interface specification and uses our color rules as constraints to determine the best colors for particular items. While ACE is only a prototype, we learned that an expert system is a viable method for choosing an initial set of colors that can be “tweaked” by a human expert. We also learned that much more research needs to be performed in the areas of visual color relationships and how they can be used to provide the most effective user interface.