title: Change 3D background to black in matplotlib
body: <p>I'm having trouble changing the background of my 3d graph to black. This is my current code. When I do set facecolor to black, it changes the inside of the graph to be grey, which is not what I want. </p>
  
  <p><a href="https://i.stack.imgur.com/QFdhJ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/QFdhJ.png" alt="enter image description here"></a></p>
  
  <pre><code>fig = plt.figure()
  fig.set_size_inches(10,10)
  ax = plt.axes(projection='3d')
  ax.grid(False)
  ax.xaxis.pane.set_edgecolor('b')
  ax.yaxis.pane.set_edgecolor('b')
  ax.zaxis.pane.set_edgecolor('b')
  
  # plt.gca().patch.set_facecolor('white')
  # plt.axis('On')
  fig.patch.set_facecolor('black')
  
  ax.scatter(xs = Z['PC1'], ys = Z['PC2'], zs = Z['PC3'], c = Z['color'], s = 90, depthshade= False)
  ax.set(title = 'test', xlabel = 'PC1', ylabel = 'PC2', zlabel = 'PC3')
  </code></pre>