JSFiddle - React, Tailwind, and code Playground

by Qwerty_Wasd

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.js"></script>
<table>
  <tr>
    <td>
      5
    </td>
    <td>
      -7
    </td>
    <td>
      6
    </td>
    <td>
      0
    </td>
    </tr>
    <tr>
      <td>
        55
      </td>
      <td>
        85
      </td>
      <td>
        -125.32
      </td>
      <td>
        -122
      </td>
      </tr>
</table>

CSS

td {
  background: blue;
}

.below {
  background: red;
}

JavaScript

$('td').each(function () {
  var item = $(this);
  var value = parseInt($.trim(item.text()));

  if (value < 0) {
    item.addClass('below');
  }
});