A choropleth map of global economies uses color to encode categorical income groups, with a linked legend enabling interactive filtering. Clicking a legend category dims unmatched countries and the map sphere, while highlighting the selected group on both map and legend. The visualization employs d3.geoPath and d3.geoNaturalEarth1 for map projection, d3.zoom for pan and zoom, and d3.scaleOrdinal with schemeSpectral for color encoding. Data comes from the World Atlas TopoJSON and TSV files, rendered as SVG.