Color monitors are in wide use in computer systems. Thus, it is important to understand how to apply color effectively in computer assisted instruction (CAI) and computer based training (CBT). Color can enhance learning, but it does not automatically do so. Indiscriminate application of color can mislead a student and thereby even interfere with learning. Research is equivocal about the effectiveness of color in instruction, and the application of color in instructional materials is still more of an art than a science. Nevertheless, there is some knowledge from research and practical experience for guidance. For example, color enhances learning by motivating students, attracting attention, emphasizing important elements, locating information, adding structure, supporting memory and recall, differentiating among elements, tying together related items, and adding visual cues. Variables that interact with color include the characteristics of the learner, the nature of the learning task, and environmental factors. The implications of this research for instruction is that color use must be standardized in a lesson, and used consistently and conservatively. (9 references) (DB)