This choropleth map colors countries by their economic classification using a categorical ordinal color scale from `d3.scaleOrdinal` with the `schemeSpectral` palette. It renders world geography with `d3.geoPath` and a Natural Earth projection, loading TopoJSON country boundaries and TSV metadata from the world-atlas package. A custom color legend built with D3 selections appears alongside the map, while `d3.zoom` enables panning and zooming. The visualization uses SVG elements and includes hover effects that highlight individual countries.