Interindividual behavioural differences, consistent over time and across situations, are frequently related to differences in reproductive success, susceptibility to disease and competitive ability. The behavioural phenotype of a conspecific is likely to affect the outcome of a social interaction, so an individual must be able to accurately assess behavioural phenotypes in order to optimize behavioural responses during mate choice, cooperative relationships and agonistic interactions. However, behavioural assessment based on dyadic interactions in different contexts can be costly because it may require significant time, increase the risk of predation and often necessitates special cognitive abilities. Different colour cues are associated with different life history strategies in many species, so coloration might also correlate with behavioural phenotype. Thus, conspecifics could use coloration as a single cue for the mediation of social interactions. We investigated the relationship between personality and coloration in the monogamous, biparental convict cichlid. This species has black melanin-based stripes with interindividual variation in the intensity of these stripes. In addition, females have bright orange spots on their abdomens. Using repeatable measures of boldness, exploration and aggressiveness, we were able to define a behavioural syndrome and quantified the behavioural type of each individual. Behavioural types were predicted by colour traits. In particular, proactive individuals (more aggressive, bolder and quicker to resume behaviour after being startled) were more likely to be dark and, among females, have smaller orange areas. Our results support the hypothesis that coloration in the convict cichlid is related to personality. Thus, coloration could play an important role in mediating social interactions, allowing a quick and reliable assessment of conspecifics' behavioural types.