Unclassed Choropleth Map

http://www.princeton.edu/~rvdb/JAVA/election2004/purple_america_2004_small.gif

In a conventional unclassed choropleth map, a continuous area of shading or coloring is used. An interesting feature of an unclassed map is that each value has a unique shading or coloring. This characteristic requires just as many unique values or data in the map.