A horizontal bar chart displays CSS named colors as stacked rows, each colored by its hex value and sized by category. The visualization loads color data from a gist-hosted CSV file using `d3.csv` within a React component. The app uses React hooks (`useState`, `useEffect`) to manage asynchronous data loading and renders the color swatches as divs with inline styles. The `message` utility calculates and displays the data size in kilobytes using `d3.csvFormat`.