title: Chartjs multiple line tooltip with color boxes for each line
body: <p>How to add color box on chartjs multiline tooltip?</p>
  <p><a href="https://i.stack.imgur.com/ksCmy.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ksCmy.png" alt="enter image description here" /></a></p>
  <p>What I did for multiple line is:</p>
  <pre><code>    mode: 'single',
      callbacks: {
          afterBody: function(data) {
              var multistringText = ['first string'];
              // do some stuff
              multistringText.push('another string');
  
              return multistringText;
          }
      }
  }
  
  But I wanted a color box along with the multiple text with different color on them.
  The code is from: https://stackoverflow.com/questions/29302392/chartjs-tooltip-line-breaks
  </code></pre>