Any parcel map, election-district map, or school-boundary map runs into the same small design problem eventually: two adjacent polygons end up the same color, and the boundary between them disappears. Doing this by hand for anything beyond a handful of features gets tedious fast — so after running Esri's Polygon Neighbors tool in ArcGIS Pro, the natural next step was to automate the coloring decision itself.
How it works
The script reads the adjacency table produced by Polygon
Neighbors, then sorts polygons by neighbor count so the
highest-connectivity features get assigned first — a
standard graph-coloring trick that makes the whole assignment
more efficient. Each polygon gets a Color ID from 1–10,
chosen so that no two polygons sharing an edge ever get the same
value, and the script adds a Color_ID field to the
feature class and populates it automatically.
Where it's useful
Anywhere adjacency actually matters for legibility: parcel and zoning maps, election districts, school attendance boundaries, or any polygon dataset where a shared-color edge would read as a missing boundary rather than a design choice.
View the script on GitHub — buschbrian/colorID.py.