title: Trouble with setting background color for Line chart at Chartjs version 3.5.1
body: <p>I've updated my chartjs version to 3.5.1 and I cant set my background color for line chart. Border color is still active. Here is my code:</p>
  <pre><code>const labels = [
    'January',
    'February',
    'March',
    'April',
    'May',
    'June',
  ];
  const data = {
    labels: labels,
    datasets: [{
      label: 'My First dataset',
      backgroundColor: 'rgb(255, 99, 132)',
      borderColor: 'rgb(255, 99, 132)',
      data: [0, 10, 5, 2, 20, 30, 45],
      fill: true,
    }]
  };
  this.chart = new Chart(ctx, {
    type: 'line',
    data: data,
    options: this.options,
  })
  </code></pre>
  <p>And the result is:
  <a href="https://i.stack.imgur.com/vJOxM.png" rel="nofollow noreferrer">enter image description here</a></p>
  <p>Thanks for your help!</p>