We describe a set of color-graphics routines that permit implementing perceptual learning studies onIBM PCs. Stimulus items may be presented in 320×200 graphics mode, using 4 colors from a 16-color palette. There are 256 levels of stimulus clarification that may be either subject-paced, in which case the subject makes keypresses until the stimulus can be identified, or program-paced. The perceptual learning task may involve either mask clarification or dot clarification. A description of the present level of development of the procedures, and of several demonstration experiments, is presented.