JSFiddle - React, Tailwind, and code Playground

HTML

<div class="time"></div>

JavaScript

function time(el) {
    var today = new Date();
    var hour = today.getHours();
    var minute = today.getMinutes();
    var second = today.getSeconds();
    var line = "&ndash;";
    var twoPoints;
    
    el.innerHTML = hour+':'+minute+':'+second;

    if (second % 2 == 0){
        el.style.color="red";
    } else {
        el.style.color="green";
    }
} 

var el = document.querySelector('.time');
    
setInterval(function(){
   time(el);
})