Cartographica can draw a background color behind all visible features in order to make the features stand out. Although this may be desirable for maps that are vector-based and have no styles, it can be distracting for choropleth maps.
You can change the background color for an individual map and also change it for all new maps going forward.
Changing the background color of a map
Choose> to bring up the Color Picker
Select or create a color of your choosing
Drag the color sample from the Color Picker to the Map View
Close the Color Picker