JSFiddle - React, Tailwind, and code Playground

HTML

<p id="phrase">Toto is the best of all people in the world</p>

CSS

.red {
    color:red;
}

JavaScript

$(document).ready(function() {
   console.log( "ready!" );
   var text = $("#phrase").html().replace(/e/g, '<span class="red">e</span>');
    $("#phrase").html(text)
});