Univariate Choropleth

http://www.clearlyandsimply.com/clearly_and_simply/2009/06/multicolored-choropleth-maps-with-excel.html

Univariate choropleth maps are a type of choropleth map that show just one variable distributed over a set area. This map shows what people most likely call "soda" throughout the United States. The Northwest mostly calls it "Pop" while most of the Southeast calls all soda "Coke".