JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        .container {
            display: flex;
        }
        .color {
            width: 100px;
            height: 100px;
            background: red;
            border-radius: 50%;
            margin-left: 20px;
        }

        .color_active {
            width: 100px;
            height: 100px;
            background: blue;
            border-radius: 50%;
            margin-left: 20px;
        }
    </style>
       
    <script>
        window.addEventListener('DOMContentLoaded', change);

        var color,
            flag = 0;

        function change() {
            color = [...document.getElementsByClassName('color')];
            setTimeout(act, 500);
        }

        function act() {
            var lenCol = color.length;

            if (flag < lenCol) {
                color.filter((f => f.style.background = 'blue'))[flag];
                console.log(color[flag]);
                flag++;
            } else {
                [...color].forEach(her => her.style.background = 'green');
                flag=0;
            }
            
            setTimeout(act, 500);
        }
    </script>
</head>
<body>
    <div class='container'>
        <div class="color"></div>
        <div class="color"></div>
        <div class="color"></div>
        <div class="color"></div>
    </div>
</body>
</html>