JSFiddle - React, Tailwind, and code Playground

HTML

<table>
  <thead>
    <tr>
      <th rowspan="2">State</th>
      <th rowspan="2">Utilities Company</th>
    </tr>
    <tr>
      <th>data1</th>
      <th>data2</th>
      <th>data3</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>State name</td>
      <td>Utility co</td>
      <td>Data for 1</td>
      <td>Data for 2</td>
      <td>Data for 3</td>
    </tr>
    <tr>
      <td>State name</td>
      <td>Utility co</td>
      <td>Data for 1</td>
      <td>Data for 2</td>
      <td>Data for 3</td>
    </tr>
    <tr>
      <td>State name</td>
      <td>Utility co</td>
      <td>Data for 1</td>
      <td>Data for 2</td>
      <td>Data for 3</td>
    </tr>
    <tr>
      <td>State name</td>
      <td>Utility co</td>
      <td>Data for 1</td>
      <td>Data for 2</td>
      <td>Data for 3</td>
    </tr>
    <tr>
      <td>State name</td>
      <td>Utility co</td>
      <td>Data for 1</td>
      <td>Data for 2</td>
      <td>Data for 3</td>
    </tr>
  </tbody>
</table>

CSS

table {
  border-collapse: collapse;
}

td, th {
  border: 1px solid Black;
  padding: 5px 15px;
}

thead > tr:nth-child(1) > th:nth-child(1) { background-color: Orchid; }
thead > tr:nth-child(1) > th:nth-child(2) { background-color: YellowGreen; }
thead > tr:nth-child(1) > th:nth-child(3) { background-color: Orange; }
thead > tr:nth-child(2) > th              { background-color: Gold; }