This example shows a color wheel built from CSS named colors, where each color is represented as a slice of a pie chart rendered as SVG. The visualization uses React’s `useState` and `useEffect` hooks to asynchronously load a CSV file via d3.csv, storing the fetched data in state before rendering. Each slice’s path is generated with d3.arc, mapping the data’s RGB hex values to fill colors. While data loads, a simple “Loading…” message appears. The code relies on React 16.9 and d3 v7.