This choropleth map colors countries by economic classification using an ordinal color scale derived from d3.scaleOrdinal and d3.schemeSpectral. The visualization renders geographic boundaries with d3.geoPath and a natural Earth projection, with zooming enabled via d3.zoom. Hover effects highlight individual countries, and a custom color legend built with SVG circles and text explains the color categories. Country names and economic data are loaded from TopoJSON and TSV files using d3.json and d3.tsv.