We examined interference effects of emotionally associated background colours during fast valence categorisations of negative, neutral and positive expressions. According to implicitly learned colour–emotion associations, facial expressions were presented with colours that either matched the valence of these expressions or not. Experiment 1 included infrequent non-matching trials and Experiment 2 a balanced ratio of matching and non-matching trials. Besides general modulatory effects of contextual features on the processing of facial expressions, we found differential effects depending on the valance of target (...) facial expressions. Whereas performance accuracy was mainly affected for neutral expressions, performance speed was specifically modulated by emotional expressions indicating some susceptibility of emotional expressions to contextual features. Experiment 3 used two further colour–emotion combinations, but revealed only marginal interference effects most likely due to missing colour–emotion associations. The results are discussed with respect to inherent processing demands of emotional and neutral expressions and their susceptibility to contextual interference. (shrink)