Facial expressions of emotion include both muscular and color modulations that contribute to the accurate perception of emotion. However, some emotion categories share common facial-muscular features during the dynamic expressive sequence, which can lead to confusion and misidentification. The current research posits that a potential social function of facial-color expression lies in its ability to disambiguate confusing facial-muscular emotion expressions. In Experiment 1, participants were asked to rate and categorize confusing emotion expressions (i.e., mixed anger-disgust) that varied in facial color (i.e., CIELAB a*, red-green axis). The results showed that changes in facial color facilitated the disambiguation of the confusing emotion expressions for both ratings and categorizations. In Experiment 2, participants were asked to change the color on faces with either disgust, confusing, or anger expressions, to match the emotion being expressed. The results showed that participants differentially used color information to make the faces maximally expressive. Additionally, participants in Experiment 2 consistently applied facial color changes regardless of disambiguating information provided by either explicit instructions or validated expressions. The findings from the current research support a social functional account of facial color in the communication of emotion; facial color makes a unique contribution to emotion expression, independent of facial musculature.