The purpose of this study is to investigate the influences of surround relative luminance on the appearance of colour images presented on a large display. Psychophysical experiments were conducted under four surround conditions, i.e. dark, dim and bright surrounds excluding flare, as well as a typical office surround. Fourteen observers were asked to assess image quality and the three perceptual appearances, colourfulness, naturalness and contrast, using the categorical judgment method. Five colour images were manipulated to produce variations by rendering lightness, chroma and sharpness. These manipulated images were used as the stimuli in the assessment. The experimental results show that there were significant differences between the four surround conditions for dark images in terms of image quality and the three perceptual appearances, in particular colourfulness. In addition, naturalness was found to be the critical factor affecting image quality for all surrounds.