title: Invalid rgba arg "#" in matplotlib
body: <p>I can't figure out how to use colours while trying to create a scatter plot in matplotlib.</p>
  
  <p>I'm trying to plot multiple scatter plots with different colour points to show the clusters.</p>
  
  <pre><code>colors=['#12efff','#eee111','#eee00f','#e00fff','#123456','#abc222','#000000','#123fff','#1eff1f','#2edf4f','#2eaf9f','#22222f'
          '#eeeff1','#eee112','#00ef00','#aa0000','#0000aa','#000999','#32efff','#23ef68','#2e3f56','#7eef1f','#eeef11']
  C=1
  fig = plt.figure()
  ax = fig.gca(projection='3d')
  for fgroups in groups:
     X=[np.random.rand(50),np.random.rand(50),np.random.rand(50)]
     y=[np.random.rand(50),np.random.rand(50),np.random.rand(50)]
     Z=[np.random.rand(50),np.random.rand(50),np.random.rand(50)]
     C=(C+1) % len(colors)
     ax.scatter(X,Y,Z, s=20, c=colors[C], depthshade=True)
  plt.show()
  </code></pre>
  
  <p>The error I'm getting is as follows:</p>
  
  <blockquote>
    <p>ValueError: to_rgba: Invalid rgba arg "#"
    to_rgb: Invalid rgb arg "#"
    could not convert string to float: #</p>
  </blockquote>
  
  <p>It seems like its treating these rgb arguments as floats.</p>
  
  <p>However in the matplotlib docs colors are written in this style <a href="http://matplotlib.org/api/colors_api.html" rel="noreferrer">http://matplotlib.org/api/colors_api.html</a></p>
  
  <p>What am I missing?</p>