code: function deltaE(labA, labB) {
        var deltaL = labA[0] - labB[0];
        var deltaA = labA[1] - labB[1];
        var deltaB = labA[2] - labB[2];
  
        return Math.sqrt(Math.pow(deltaL, 2) +
                         Math.pow(deltaA, 2) +
                         Math.pow(deltaB, 2));
      }
docs: Find the perceptual color distance between two LAB colors
  @param {Array} labA
  @param {Array} labB
  @returns {number}