This choropleth map colors countries by economy using world-atlas TopoJSON data. The visualization uses d3.geoNaturalEarth1 projection with d3.geoPath to render the map, and d3.scaleOrdinal with schemeSpectral for color encoding. The color legend, built with a custom colorLegend function, displays the ordinal scale. Interactive pan and zoom is implemented via d3.zoom, and hovering highlights countries in red.