A grid of eighteen smiley faces, each rendered with random background and eye colors, demonstrates compartmentalized React components. The faces use a combination of SVG circles for the background and eyes, and a D3 arc path for the mouth. Each face’s stroke width, eye offset, eye radius, and mouth dimensions are randomized via JavaScript’s `Math.random()`. The React app maps over a D3 range to generate the faces, while the `randomColor.js` utility builds hex color strings for the fills.