This choropleth map colors countries by economy using a spectral ordinal scale, and includes an interactive color legend with circles and labels. The visualization renders world geography via a natural Earth projection and supports zooming and panning through d3.zoom. Data comes from the World Atlas TopoJSON and TSV files, processed with topojson.feature. The code imports individual D3 v5 modules including geoPath, geoNaturalEarth1, and scaleOrdinal, and builds the legend with a custom colorLegend function.