A pie chart visualizes the relative frequency of CSS named colors by rendering each color as a slice of equal size, filled with its corresponding RGB hex value. The example loads color data from a CSV file using `d3.csv`, then computes the pie layout with `d3.pie` and generates SVG paths via `d3.arc`. React manages the component state and renders the SVG elements, while D3 handles the data loading and geometric calculations. The visualization highlights the color names themselves, with each slice showing the actual color it represents.