title: SCNBox different colour or texture on each face
body: <p>I'm new to iOS development and I've got myself stumped. I am trying to render a cube using SceneKit that has a different colour for each face.</p>
  
  <p>This is what I've got so far:</p>
  
  <pre><code>func sceneSetup() {
      // 1
      let scene = SCNScene()
  
      // 2
      let BoxGeometry = SCNBox(width: 0.9, height: 0.9, length: 0.9, chamferRadius: 0.0)
  
      BoxGeometry.firstMaterial?.diffuse.contents = UIColor.redColor()
      let cube = SCNNode(geometry: BoxGeometry)
      cube.position = SCNVector3(x: 0, y: 0, z: -1)
      scene.rootNode.addChildNode(cube)
  
      // 3
      sceneView.scene = scene
      sceneView.autoenablesDefaultLighting = true
      sceneView.allowsCameraControl = true
  </code></pre>
  
  <p>But I'd like each face to have a different colour. How do I do that?</p>