title: How to custom the color of each bar of a bar chart in flutter?
body: <p>I am new to flutter and try to build a bar chart with different colors. I use the chart dependency provided by google.  </p>
  
  <p><a href="https://google.github.io/charts/flutter/gallery.html" rel="nofollow noreferrer">https://google.github.io/charts/flutter/gallery.html</a></p>
  
  <p>However, I find I could only change the color of all bars. Is there anyway I could custom the color of one specific bar? 
  I have searched online and no such information are posted.</p>