In 1893, terra cotta and white were chosen as the official colors for decorations at the Columbian Exposition. The colors symbolized the importance of terra cotta in Chicago's building industry.
The white Y is the Chicago municipal device and its three parts indicate the three Chicago divisions, north, west, and south. Terra cotta and white were chosen to be Chicago's municipal colors right before the World's Columbian Exposition.
On September 11, 1892, the Chicago Tribune sponsored a contest seeking municipal colors that would be used prominently throughout Chicago during the 1893 World's Columbian Exposition of 1893. After receiving 892 entries, the contest judges selected the submission of A. J. Roewad, a Danish immigrant whose design featured a white inverted Y set on a background of red. In his submission, Roewad wrote that the three parts [of the Y] indicate the three Chicago divisions North, West and South united with a white or silver band which represented the Chicago River. Though the color scheme of white and terra cotta, meant to symbolize the importance of terra cotta in Chicago's building industry, lost favor over the years, the Y symbol soon became a part of Chicago's municipal code. On April 15, 1917, the Y became known as the Chicago Municipal Device. It can still be seen in the facades of various buildings around the city.