Manual Cued Speech is a system of hand gestures designed to help deaf speechreaders distinguish among ambiguous speech elements. We have developed a computerized cueing system that uses automatic speech recognition to determine and display cues to the cue receiver. Keyword scores of 66% in low-context sentences have been obtained with this system, almost double the speechreading-alone scores. We describe the design issues with the largest impact on the cuer's performance, concentrating on the characteristics of cue display and cue timing. Enhancing cue images with color is found to improve their discriminability and may lead to improved speech reception by cue receivers.