title: How to plot below x axis area with a different color in python?
body: <p>I am plotting a time series in python and for better visualization, I want to plot below axis area with a different color. Below is the code I am using.</p>
  <pre><code>import matplotlib.pyplot as plt
  plt.plot(list2,spi1,color = 'black')
  plt.ylabel('Standardized precipitation index')
  plt.xlabel('Time (years)')
  plt.show()
  </code></pre>
  <p>Please help me to make it correct.
  Here is the plot-
  <a href="https://i.stack.imgur.com/3P9bq.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3P9bq.png" alt="enter image description here" /></a></p>