JSFiddle - React, Tailwind, and code Playground

HTML

<div id="out"></div>
<pre id="cnt"></pre>

CSS

span{
  color:red;
}

JavaScript

const text = 'море небо песок небо море небо';
	const search = 'небо';
  let counter = 0;
  
  // замена
	const result = text.replaceAll(search, replace);
  
  // вывод
	out.innerHTML = result;
  cnt.textContent = counter;
    
  function replace(str) {
    counter++;
    return `<span>${str}</span>`;
  }