Experiments were carried out to investigate the effect of simultaneous contrast on colour appearance by varying the lightness, colourfulness, and hue of an induction field surrounding a test colour. A total of 814 test/surround combinations were displayed on high-resolution colour displays. Each was assessed by a panel of five to six observers using a magnitude estimation technique. The results indicate that colours presented on a computer dis play are affected by simultaneous contrast in a similar way to surface colours. All three colour appearance parameters studied (i.e., lightness, colourfullness, and hue) are affected and these effects are summarized In general, the results support and add to the findings of the other studies. The Hunt colour appearance model was tested and gave a somewhat pool prediction to this data set. Further modifications are required to improve its performance.