A rotating cube constructed from 64 colored spheres demonstrates Three.js's 3D rendering capabilities. Each sphere's hue is derived from its grid position using HSL color mapping, creating a gradient across the cube's volume. The scene uses `THREE.Scene`, `THREE.DirectionalLight`, and `THREE.AmbientLight` for illumination, while `OrbitControls` enables user interaction. The animation continuously rotates the sphere group, and the WebGL renderer displays the result in a black background.