Colour context effects on speeded valence categorization of facial expressions

Colour often has emotional connotations, with red associated with negativity and green with positivity. Some suggest that these associations automatically influence the categorization of affective stimuli presented in their context. If so, such effects should occur rapidly, remaining robust under temporal constraints. Here we examined whether these associations influence affective judgments about emotionally ambiguous (neutral or surprised) facial expressions when stimulus presentation duration (Experiment 1) or decision time (Experiment 2) is constrained. Faces appearing on red backgrounds were categorized as negative more than those on green or grey backgrounds, regardless of presentation duration or decision time. Faces on green backgrounds were also categorized as positive more than those on grey backgrounds when decision time was constrained. When incongruent with the expressed emotion, background colour also interfered with affective judgments about emotionally unambiguous faces (Experiment 3). Our findings suggest colour associations rapidly impact valence judgments and potentially operate outside participants’ control.