This study investigated whether a particular palette of colours is used by graphic designers for fiction book covers in the Romance, Science Fiction, and Mystery/Thriller genres. The results show that in the Romance genre the predominant cover colours were skin tone (43%), peach (20%), brown/black (18%) and mid red/brown (10%). In the Science Fiction genre there were five predominant colours: almost black (35%), light off-pink (20%), mid off grey (15%), light grey blue (15%), and mid brown/orange (10%). The Mystery/Thriller genre covers had four predominant colours: skin tone (40%), almost black (20%), mushroom (10%) and mid grey (10%). Overall, for all genres, the statistical analysis revealed that there were numerous significant differences between the genres for these predominant colours and that the predominant colours included both low and high lightness colours, but very few high saturation colours.