JSFiddle - React, Tailwind, and code Playground

HTML

<html>
  <body>
    <h4>Two rows and three columns:</h4>
      <table border="1" width="100%" height="400" align="top">
        <tr style="height: 1">
          <td>
            <table width="100%" border="2" height ="100" align="top">
              <tr>
                 <td id="cell">1-1</td> <!-- R1C1 Yellow -->
                 <td>1-2</td> 
               </tr>
               <tr>
                 <td>1-3</td>
                 <td>1-4</td>
               </tr>
             </table>
          </td> 
          <td>
            <table width="100%" border="2" height ="100" align="top">
               <tr>
                 <td>2-1</td>
                 <td>2-2</td> 
               </tr>
               <tr>
                 <td>2-3</td>
                 <td>2-4</td>
               </tr>
             </table>
          <td>
            <table width="100%" border="2" height ="100" align="top">
               <tr>
                 <td>3-1</td>
                 <td>3-2</td> 
               </tr>
               <tr>
                 <td>3-3</td>
                 <td>3-4</td>
               </tr>
           </table>
         </td> 
       </tr>
       <tr style="vertical-align: top">
         <td>
           <table width="100%" border="2" height ="100">
               <tr>
                 <td>4-1</td>
                 <td>4-2</td> 
               </tr>
               <tr>
                 <td>4-3</td>
                 <td>4-4</td>
               </tr>
          </table>
         <td>
           <table width="100%" border="2" height ="100">
               <tr>
                 <td>5-1</td>
                 <td>5-2</td> 
               </tr>
               <tr>
                 <td>5-3</td>
                 <td>5-4</td>
               </tr>
             </table>
          <td> 
             <table width="100%" border="2" height ="100">
               <tr>
                 <td>6-1</td>
                 <td>6-2</td> 
               </tr>
               <tr>
                ...

CSS

.highlight {
    background-color: #FFFF00;
}

JavaScript

var elapsed = 0;
var interval = 250;
var duration = 3000;

function toggle(element) {
    var newClass = element.className == 'highlight' ? '' : 'highlight';
    element.className = newClass;
    elapsed += interval;
    
    if(elapsed < duration)
        setTimeout(function() { toggle(element); }, interval);
}

var element = document.getElementById('cell');
toggle(element);