JSFiddle - React, Tailwind, and code Playground

HTML

<div id="blink"><span>Demo</span>
</div>

CSS

#blink {
  text-align: center;
  background: #c6c6c6;
  color: #fff;
  margin: 0;
  padding: 20px;
}
#blink span {
  font-size: 2em;
  font-weight: bold;
  display: block;
}

JavaScript

$(document).ready(function(){
    var myVar;
    myVar = setInterval(blinkFont, 500); 

    function blinkFont() {
    var curColor = document.getElementById("blink").style.color;
    var curBgC = document.getElementById("blink").style.background;
    document.getElementById("blink").style.color = curColor === "red" ? "blue" : "red";
    document.getElementById("blink").style.background = curBgC === "black" ? "yellow" : "black";

}
    setTimeout(function () {
                     $("#blink").css('visibility', 'visible');
        clearInterval(myVar);        
                }, 15000); // after 3 seconds it'll stop blinking
});