This choropleth map colors world countries by their economic classification using a categorical color scale derived from d3.scaleOrdinal and d3.schemeSpectral. It draws geographic boundaries with d3.geoPath and a natural Earth projection, with hover highlighting and zooming via d3.zoom. Country metadata—including economy and income group—comes from a TSV file joined to TopoJSON geometry, and a custom legend component renders the color domain as circles with labels.