title: similar to seaborn's hue function in plotly?
body: <p><a href="https://i.stack.imgur.com/eA7kz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eA7kz.png" alt="enter image description here"></a></p>
  
  <pre><code>geo1 = go.Scatter(
  x=geo['Year'],
  y=geo['Number'],
  mode='lines',
  marker=dict(color=geo['Geographical region'],size=4, showscale=False),
  name='geo',
  showlegend=True)
  
  
  data = [geo1]
  
  layout = dict(
  title='Working VISA in UK by Regions',
  xaxis=dict(title='Year'),
  yaxis=dict(title='Number'), showlegend=True)
  fig = dict(data=data, layout=layout)
  iplot(fig)
  </code></pre>
  
  <p>The result shows:
  <a href="https://i.stack.imgur.com/tqC1I.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/tqC1I.png" alt="enter image description here"></a></p>
  
  <p>what I want is to use a similar function as 'hue' in seaborn:
  <a href="https://i.stack.imgur.com/yTe05.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/yTe05.png" alt="enter image description here"></a></p>
  
  <p>how to do the plotly coding by regions in different colors?</p>