Color Choropleth for GIS Communication

This week we experimented with managing and creating color ramps, using ArcGIS Pro and the online Colorbrewer application. This was a great series of exercises to help with the understanding of what colors to use, when, and the classification methods that work best for representing the data.

Below are three color ramps with details, including their intervals and step size. The first two were configured using ArcGIS Pro and the third using a similar ramp in Colorbrewer. In this case, the Colorbrewer application appears to have the best color ramp, with the most differentiated and easy to distinguish colors of the three blue-green ramps.

I like how Colorbrewer has an option to use “multi” or “like” colors, instead of limiting to changing saturations of the same hues. This emphasized the change from green-blue to blue-green, which helped to separate the colors. The next best ramp appears to be the adjusted progression, which does successfully compensate to make the dark colors more distinct. It does not seem to do enough to separate the lighter hues. In the Linear progression, the color ramp works, but the colors blend together and do not compensate for audiences that may have color blindness or vision challenges - which you can set Colorbrewer to do automatically. A great assignment that introduced me to a helpful new tool, which I have certainly bookmarked for later use.