Researchers continue to study the psychological implications of seeing red. Previous research has been reported here. Wiedemann, Burt, Hill, and Barton report that “In humans, red stimuli are perceived as more threatening and dominant than other colours, and wearing red increases the probability of winning sporting contests.” They studied responses to photographs of men that were digitally altered so that those pictured were wearing red, blue, or gray clothing. They determined “Men were rated as more aggressive . . . when presented in red than when presented in either blue or grey. . . . In a categorization test, images were significantly more often categorized as ‘angry’ when presented in the red condition. . . This suggests that the colour red may be a cue used to predict propensity for dominance and aggression in human males.”
Diana Wiedemann, D. Burt, Russell Hill, and Robert Barton. 2015. “Red Clothing Increases Perceived Dominance, Aggression and Anger.” Biology Letters, vol. 11, no. 5, no pagination.