Translate Coolors.co palette to hex and rgb values in JavaScript/JSON object

CoolorsPalette.js

var cp = (function () {
  class CoolorsPalette {
    constructor() {
      // Row spans all palette columns: i.e., one shade of each color
      this.rows = Array.from(document.querySelectorAll('#palette-shades div.palette-shades-row'))
      const numCols = this.rows[0].querySelectorAll('div.palette-shades-col').length
      this.colors = Array(numCols).fill([])
      this.rows.forEach(row => {
        Array
          .from(row.querySelectorAll('div.palette-shades-col'))
          .forEach((cell, i) => { // cell = distinct color-shade 
            const hex = cell.attributes['data-color'].value
            const [r, g, b] = cell.style.background.match(/\d+/g)
            this.colors[i].push({ hex, r, g, b, cell, row }) 
          })
      })
    }
  }
  return new CoolorsPalette()
})();