This example demonstrates loading external CSV data with D3 and rendering it as a color wheel using React. The app fetches a dataset of CSS named colors via `d3.csv`, then maps each row to a pie slice using `d3.pie` and `d3.arc`. The circular chart displays each color’s hex value as its fill, producing a full spectrum. React’s `useState` and `useEffect` manage the asynchronous data loading, with a loading message shown until the CSV is available.