The university's distinctive school color originated only a few years after the university opened. Not long after the first students arrived, they organized two debating groups: the Dialectic and Philanthropic Societies. The "Di" and "Phi" societies played a large role in campus academic and social life. Early students were required to join one or the other. They proclaimed their membership by wearing ribbons in their society's color. The Phi's color was white, and the Di's color was light blue. The ribbons were also used on diplomas awarded by the society. Examples of these from the early 1800s survive today in Wilson Library.
When UNC began competing in intercollegiate sports in the late 1880s, the students followed the lead of other universities in adopting school colors. There does not appear to have been any debate: the Tar Heel athletic teams used the colors long associated with the debating societies. The light blue soon became a signature color for the university. By the 1930s newspapers were referring to it as "Carolina blue." Used in official publications and on clothing, it was embraced by students and administrators. By the end of the twentieth century the color was an inseparable part of campus life, but there were questions about the "true" Carolina blue. Printers and manufacturers used different versions of the color. The men's basketball uniforms used a darker version that was supposed to look better on television, but campus publications had a much lighter shade.
Alumnus and fashion designer Alexander Julian was particularly offended by the color of the graduate gowns he saw on students walking past his store on Franklin Street. After lobbying for several years to "improve the true blueness" of the robes, Julian was given the job of redesigning the gowns in 2010. Julian's new, "true blue" robes were worn at graduations starting in the spring of 2011. To eliminate further confusion about the proper shade of the color, the university worked with Nike in 2015 to standardize the school's athletic uniforms. In the process, the university established Pantone 542 as the official version of Carolina blue.