JSFiddle - React, Tailwind, and code Playground

HTML

<table border="1">
 <tr>
     <th>Header 1</th>
     <th>Header 2</th>
 </tr>
 <tr>
     <td>row 1, cell 1</td>
     <td>row 1, cell 2</td>
 </tr>
 <tr>
     <td>row 2, cell 1</td>
     <td>row 2, cell 2</td>
 </tr>
 </table>

JavaScript

var txt = 'Header 2';
var column = $('table tr th').filter(function() {
    return $(this).text() === txt;
}).index();

if(column > -1) {
    $('table tr').each(function() {
        $(this).find('td').eq(column).css('background-color', 'red');
    });
}