The White City
The majority of the buildings from the World's Fair were white because they were meant to be temporary. They were built with stucco and then painted with compressed-air squirt guns for quickness.
The color of the main buildings was still a matter of lively discussion in May,1892 at which time some of the structures later noted for their serene whiteness were still slated for more poly chromatic treatment...Eastern painter Francis D. Millet, who taught at the Art Institute of Chicago; but by December of 1892 Millet was proclaiming that white was the only suitable color for the Court of Honor. Many writers see the necessity of speed as a major influence on the decision that created the White City. The white paint was applied by compressed-air squirt guns, which were used here for the first time on a major project.