Adjacent Color Mapping

<p>When creating a map with many adjacent polygons, such as political boundaries or districts, adding color can be challenging. Sometimes, there’s no specific data field that needs to be visually represented, but adding color can make polygons easier to distinguish and their boundaries clearer.</p><p>If there are more than 4–5 polygons, using unique colors for each one can be overwhelming. On the other hand, relying solely on boundary outlines may not provide enough distinction.</p><p>Recently, the GIS Office created maps displaying legislative and congressional district boundaries in Connecticut, along with the corresponding representatives for each district. One particular challenge when creating these maps was designing symbology for the House of Representatives map, which included 151 districts! We needed to show both town and district boundaries clearly, but simply using outlines became too visually messy. At the same time, there were too many districts to assign unique colors to each, especially since the colors weren’t tied to specific data—they were only there to separate the districts visually.</p>