Recent research has revealed that a person or team wearing red is more likely to win a physical contest than a person or team wearing another color. In the present research, we examined whether red influences perceptions of relative dominance and threat in an imagined same-sex competitive context, and did so attending to the distinction between wearing red oneself and viewing red on an opponent. Results revealed a bidirectional effect: wearing red enhanced perceptions of one’s relative dominance and threat, and viewing an opponent in red enhanced perceptions of the opponent’s relative dominance and threat. These effects were observed across sex, and participants seemed unaware of the influence of red on their responses. Our findings lead to practical suggestions regarding the use of colored attire in sport contexts, and add to an emerging, provocative literature indicating that red has a subtle but important influence on psychological functioning.