JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tr>
        <td>30</td>
    </tr>
    
    <tr>
        <td>3</td>
    </tr>
    
    <tr>
        <td>9</td>
    </tr>
    
    <tr>
        <td>9</td>
    </tr>
</table>

JavaScript

function ModifyData( ) {
      var Elements=document.getElementsByTagName('td');
      pictureGrey="Z_led_grey.gif";

      for(var i=0;i<Elements.length;i++) {
        if(Elements[i].innerText=='3') {
            Elements[i].style.color='green';
            Elements[i].style.background='green';
            Elements[i].innerText=' ';
        }
        if(Elements[i].innerText=='9') {
             Elements[i].innerText=' ';
            var img = document.createElement("img");
            img.src=pictureGrey;
            Elements[i].appendChild (img );}
      }
    }
ModifyData();