arcgis desktop - Coloring thousands of polygons so each is distinct from its neighbors?

I am using ArcGIS 10, and I have layers of the 2010 Census blocks, block groups, and tracts. There are thousands of polygons in these layers.

I want to color them so that each is distinct from its neighbors, but all I can figure out is how to give each one a distinct color. The color of each polygon does not really matter; I just want to easily distinguish each from its neighbor by color, rather than with a border.

Or is that something you only see in an elementary school map of the 50 United States?