title: gradient clearColor in threejs
body: <p>I can get a solid clearColor in threejs, but is there a way to achieve a gradient clearColor. Or some similar way to achieve a little more depth in my sky, maybe with lights? </p>
  
  <p>Here's my relevant code:</p>
  
  <pre><code>renderer = new THREE.WebGLRenderer({ antialias: true });
  renderer.setClearColor( 0x3dc800 );
  
  var light = new THREE.HemisphereLight( 0xffffff, 0xeeeeee, 0.75 );
    light.position.set( 0.5, 1, 0.75 );
    scene.add( light );
  
  scene.fog = new THREE.Fog( 0x4ff904, 0, 750 );
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/R8ka7.jpg" alt="enter image description here"></p>