Colour is a common feature in computer-aided learning (CAL), though the instructional effects of screen colour are not well understood. This investigation considers the effects of different CAL study tasks with feedback on posttest performance and on posttest memory of the lesson colour scheme. Graduate students (n=68) completed a computer-based vocabulary lesson that included either multiple-choice or constructed-response study tasks with feedback. Each lesson section used a different colour theme, while the posttest did not use colour. The constructed-response study task was a little more effective for posttest memory of lesson content but was substantially less effective for posttest memory of the lesson colour scheme. These results show a clear interaction of screen colour and lesson study task, a memory-context effect. The practical and theoretical implications of these findings are discussed.