title: How to pass color as a function parameter in python
body: <p>I've created a function in python as follows:</p>
  <pre><code>def confidence_ints(df, color):
     time_series_df = pd.DataFrame(df)
     smooth_path = time_series_df.rolling(20).mean()
     path_deviation = time_series_df.rolling(20).std()
     plt.plot(smooth_path, linewidth=2)
     plt.fill_between(path_deviation.index, (smooth_path-2*path_deviation)[0], 
                       (smooth_path+2*path_deviation)[0], color=color, alpha=.1)
     return
  </code></pre>
  <p>I would like to call the function multiple times for different dataframes, and plot specific for colors each df.  However, when I call the function using the following code:</p>
  <pre><code>confidence_ints(dfmel_statsT_HEL, green)
  </code></pre>
  <p>I get the following error:</p>
  <p><em>NameError: name 'green' is not defined</em></p>
  <p>How do I do this correctly?</p>
  <p>Thanks.</p>