JSFiddle - React, Tailwind, and code Playground

HTML

<table id="t1">
  <tr>
    <td>1</td>
  </tr>
  <tr>
    <td>1</td>
  </tr>
  <tr>
    <td>2</td>
  </tr>
  <tr>
    <td>2</td>
  </tr>
  <tr>
    <td>2</td>
  </tr>
  <tr>
    <td>3</td>
  </tr>
  <tr>
    <td>3</td>
  </tr>
  <tr>
    <td>3</td>
  </tr>
  <tr>
    <td>3</td>
  </tr>
  <tr>
    <td>4</td>
  </tr>
  <tr>
    <td>4</td>
  </tr>
</table>

JavaScript

var objT = document.getElementById('t1');
var r = objT.rows.length;
var color = ['white', 'grey', 'blue'];
for (i = 1; i < r; i++) {
  var res_i = objT.rows[i].cells[0].innerHTML;
  var rand = Math.floor(Math.random() * color.length);
  for (j = 0; j < r; j++) {
    var res_j = objT.rows[j].cells[0].innerHTML;
    if (res_i == res_j) {
      console.log(color[rand]);
      objT.rows[j].style.background = color[rand];
    }
  }
}