title: Changing the line color in plot_surface
body: <p>I did a surface plot with some data in Python.</p>
  
  <p><img src="https://i.stack.imgur.com/APifg.png" alt="enter image description here"></p>
  
  <p>Now I tried to change the style of such a plot. But unfortunately I am stuck in the <strong>line color</strong>. It's default is black, but I want to make it red or any other color.</p>
  
  <p>My code is:</p>
  
  <pre><code>from mpl_toolkits.mplot3d import Axes3D
  
  import matplotlib.pyplot as plt
  from matplotlib import cm
  import numpy as np
  
  data=np.loadtxt("test.txt")
  
  
  def formateU(data):
     U = np.zeros((20,20))
     for value in data:
        U[value[0],value[1]] = value[2]
     return U
  
  U = formateU(data)
  
  
  y,x=np.meshgrid(np.linspace(0.,19,20),np.linspace(0.,19,20))
  
  fig = plt.figure()
  
  ax=plt.axes(projection='3d')
  
  ax.plot_surface(x,y,U,rstride=1,cstride=1,alpha=0,linewidth=0.5)
  
  ax.view_init(30, 45)
  
  plt.savefig("test.png")
  
  plt.show()
  </code></pre>
  
  <p>It' seems obvious that it has to be an additional argument in:</p>
  
  <pre><code>ax.plot_surface(x,y,U,rstride=1,cstride=1,alpha=0,linewidth=0.5)
  </code></pre>
  
  <p>but I can't figure it out.</p>
  
  <p>Can you help me please?</p>
  
  <p>The <strong>test.txt</strong> is available at <a href="http://www.file-upload.net/download-8564062/test.txt.html" rel="noreferrer">http://www.file-upload.net/download-8564062/test.txt.html</a></p>