[BETEPAH]

<style>.red {color: red}</style>
    <p class="hello">Lorem ipsum dolor sit amet, consectetur</p>
    <p class="hello">Sapiente in delectus dolorem reiciendis ditii</p>
    <p class="hello">Quis dolore autem voluptatibus repellat</p> 
<script>
(function (nameClass, addThis) {
  var classes = document.getElementsByClassName(nameClass);
  for(var i = 0; i < classes.length; i++) {
    setTimeout(addClass.bind(false, classes[i], addThis), i*2000 + 2000);
  }
})("hello", "red");
function addClass(o, c){
    var re = new RegExp("(^|\\s)" + c + "(\\s|$)", "g")
    if (re.test(o.className)) return
    o.className = (o.className + " " + c).replace(/\s+/g, " ").replace(/(^ | $)/g, "");
}
</script>