JSFiddle - React, Tailwind, and code Playground

HTML

<div id=div>Блок</div>

JavaScript

var r=255;
var g=255;
var b=255;
function transfuse(){
obj=document.getElementById("div");
obj.style.background="rgb("+r+","+g+","+b+")";
r--;
g--;
b--;
if(r>100)setTimeout("transfuse()",10);
}
transfuse();