Edit in JSFiddle

// custom list of colors for font and table color widgets
textboxio.replace('#editableDiv', {
  ui: {
    colors: {
      buttons: [
        { value: 'green' },
        { value: 'yellow' },
        { value: 'red' },
        { value: 'orange', text: 'A bright background color' },
        { value: '#062f70', text: 'navy' },
      ]
    }
  }
});

<div id="editableDiv">
  <p>This is the Editor content</p>
  <table border="1" style="border-collapse: collapse; width: 100%;">
    <tbody>
      <tr>
        <td style="width: 33%;">
          <br />
        </td>
        <td style="width: 33%;">
          <br />
        </td>
        <td style="width: 33%;">
          <br />
        </td>
      </tr>
    </tbody>
  </table>
</div>