title: How to create color gradient on Google Visualization Line Chart
body: <p>I am creating a Google line chart as per <a href="https://developers.google.com/chart/interactive/docs/gallery/linechart" rel="nofollow">Google Line Chart Documentation</a>.</p>
  
  <p>I want to style the colour of the line such that it is a gradient between two colours, say between Green and Red. The weighting of each colour should be controlled by the 'y' value of the line.</p>
  
  <p>i.e. at the point where the line's 'y' value is 0, the line will be completely green, At the highest 'y' value on the it should be completely red. In between values should have a weighting depending on the value of y at that point.</p>
  
  <p>Is this possible? If so, how? </p>