Chart.js plugin to display labels on pie, doughnut and polar area chart. 

            {
              labels: {
                render: 'label'
              }
            }
          
            {
              labels: {
                render: 'percentage',
                fontColor: ['green', 'white', 'red'],
                precision: 2
              }
            }
          
            {
              labels: {
                render: 'percentage',
                fontColor: function (data) {
                  var rgb = hexToRgb(data.dataset.backgroundColor[data.index]);
                  var threshold = 140;
                  var luminance = 0.299 * rgb.r + 0.587 * rgb.g + 0.114 * rgb.b;
                  return luminance > threshold ? 'black' : 'white';
                },
                precision: 2
              }
            }
          
            {
              labels: {
                render: 'value',
                fontSize: 14,
                fontStyle: 'bold',
                fontColor: '#000',
                fontFamily: '"Lucida Console", Monaco, monospace'
              }
            }
          
            {
              labels: {
                render: function (args) {
                  return '$' + args.value;
                },
                arc: true
              }
            }
          
            {
              labels: {
                render: 'label',
                arc: true,
                position: 'border'
              }
            }
          
            {
              labels: {
                render: 'label',
                fontColor: '#000',
                position: 'outside'
              }
            }
          
            {
              labels: {
                render: 'label',
                arc: true,
                fontColor: '#000',
                position: 'outside'
              }
            }
          
            {
              labels: {
                render: 'image',
                images: [
                  { src: 'taiwan.png', width: 32, height: 22 },
                  { src: 'jpan.png', width: 32, height: 22 },
                  { src: 'usa.png', width: 32, height: 22 }
                ]
              }
            }
          
            {
              labels: [
                {
                  render: 'label',
                  position: 'outside'
                },
                {
                  render: 'percentage'
                }
              ]
            }

Polar Area

            {
              labels: [
                {
                  render: 'label',
                  fontColor: '#000',
                  position: 'outside'
                },
                {
                  render: 'percentage',
                  fontColor: ['green', 'white', 'red'],
                  precision: 2
                }
              ]
            }

Bar Chart

            {
              labels: {
                render: 'value'
              }
            }
          
            {
              labels: {
                render: 'percentage'
              }
            }
          
            {
              labels: {
                render: 'value'
              }
            }