title: bi-directional bar chart with annotation in python plotly
body: <p>I have a pandas dataset with a toy version that can be created with this</p>
  <pre><code>#creating a toy pandas dataframe
  s1 = pd.Series(['dont have a mortgage',-31.8,'have mortgage',15.65])
  s2 = pd.Series(['have utility bill arrears',-21.45,'',0])
  s3 = pd.Series(['have interest only mortgage',-19.59,'',0])
  s4 = pd.Series(['bank with challenger bank',-19.24,'bank with a traditional bank',32.71])
  
  df = pd.DataFrame([list(s1),list(s2),list(s3),list(s4)], columns = ['label1','value1','label2','value2'])
  </code></pre>
  <p>I want to create a bar chart that looks like this version I hacked together in excel</p>
  <p><a href="https://i.stack.imgur.com/oe1wy.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/oe1wy.png" alt="enter image description here" /></a></p>
  <p>I want to be able to supply RGB values to customise the two colours for the left and right bars (currently blue and orange)</p>
  <p>I tried different versions using “fig.add_trace(go.Bar” but am brand new to plotly and cant get anything to work with different coloured bars on one row with annotation under each bar.</p>
  <p>All help greatly appreciated!</p>
  <p>thanks</p>