title: Change marker/color in 3D scatter plot based on condition
body: <p>I want to do a 3D scatter plot in Python with matplotlib where for example points > 5 are shown red and the rest is blue. </p>
  
  <p>The problem is that I still get all values plotted with both markers/colors and I also know why this is the case but I'm not deep enough into Python thinking to fix this problem.</p>
  
  <pre><code>X = [3, 5, 6, 7,]
  Y = [2, 4, 5, 9,]
  Z = [1, 2, 6, 7,]
  
  #ZP is for differentiate between ploted values and "check if" values
  
  ZP = Z
  
  for ZP in ZP:
  
      if ZP &gt; 5:
          ax.scatter(X, Y, Z, c='r', marker='o')
      else:
          ax.scatter(X, Y, Z, c='b', marker='x')
  
  plt.show()
  </code></pre>
  
  <p>Maybe the solution is also something I haven't learned yet but in my mind it shouldn't be hard to get this working. </p>