Edit in JSFiddle

<table>
  <tbody>
    <tr>
      <td>Colonko</td>
      <td class="loltd">Lol colonko</td>
      <td>Colonko</td>
    </tr>
    <tr>
      <td>Colonko</td>
      <td colspan="2">Colonko</td>
    </tr>
  </tbody>
</table>
table {
  border-collapse: collapse;
  border-spacing: 0;
}

table tr td {
  border: 1px solid#ccc;
}

table tr td.loltd {
    border-bottom: 5px solid red;
}