Antti,
My requirement is exactly similar to an election map - showing 'Red/Blue' counties based on the total votes polled, for a given state.
This needs to be embedded in a web page and would prefer a solution based on Arcgis developer online, though I can install the Desktop version.
Could you please confirm my understanding?
1. Overlay the state map with a shapefile that provides county borders.
2. need to add a feature layer ( referring to the example of the ClassBreakRenderer you shared) that is specific to my usecase. If I can build a feature layer, do I need to do the step 1?
Thanks for providing references.