title: Colormapping pie plots of pandas series
body: <p>I have a double donut chart and I know how to colormap if I plot a DF, but that doesn't work with a series. How to put:</p>
  
  <pre><code>colors=outside['group1'].map(colors_outside),
  colors=middle['group2'].map(colors_middle),
  </code></pre>
  
  <p>within the <code>plt.pie()</code> part? This is the example code:</p>
  
  <pre><code>df1   = pd.DataFrame({'group1': ['bar', 'bar', 'baz', 'baz', 'baz', 'baz'], 
                    'group2': ['one', 'two', 'one', 'two', 'three', 'four'],
                'count': np.random.randint(1,5, 6)})
  
  # making the colormap
  colors_outside = {'bar': '#FF1493', 'baz': '#FFFF00'}
  colors_middle= {'one': '#FF3F33', 'two': '#8175E1','three':'#0A0096', 'four':'#960028'}
  outside = df1.groupby('group1')['group1'].count()
  middle =  df1.groupby(['group1','group2']).count()
  
  # making the donut
  plt.pie(outside, startangle=90, labels=outside.index)   # here I need: colors=outside['group1'].map(colors_outside),
  plt.pie(middle, radius=0.75, labels=labels, startangle=90,  labeldistance=0.75 ) # here I need: colors=middle['group2'].map(colors_middle),
  centre_circle = plt.Circle((0,0),0.5,color='black', fc='white')
  
  fig = plt.gcf()
  fig.gca().add_artist(centre_circle)
  plt.axis('equal')
  plt.tight_layout() 
  plt.show()
  </code></pre>