Louisiana State University (the university) (plaintiff) used the color combination of purple and gold to represent the university. The university used the colors for over 100 years for campus signage, merchandise, printed literature sent to students, alumni, faculty, and the public, and athletic uniforms, among many other things. The color combination was immediately recognizable to anyone familiar with the university. The university did not own a registered trademark for the color combination. Smack Apparel Company (defendant) designed and sold T-shirts to college sports fans. Smack’s apparel used a school’s colors and generally contained a slogan or other short phrase somehow connected to the school. One such shirt used the university’s purple and gold colors and words describing the university’s appearance in the 2004 Sugar Bowl. The university and other universities sued Smack for trademark infringement. The university claimed that not every use of the purple and gold color combination constituted a trademark violation, but only those where the colors were used in conjunction with some other identifying reference to the school. The university licensed the color combination with other identifying indicia to a licensing agent, and sales were in the millions of dollars annually. Smack acknowledged that it used certain color combinations to call certain schools into consumers’ minds. The district court granted the university summary judgment. Smack appealed.