title: How do I set background color of Line Series chart in Flex
body: <p>I have a Line Series Chart in Flex with values from 0 to 90. I would like to set the background of the chart in such a way that, 0 - 30 is in green, 31 - 60 is in red and 61 - 90 is in blue.</p>
  
  <p>I am new to Flex. Can someone tell me how this can be done?</p>