<html>
<head>
    <style>
        #grad {
            height: 50px;
            width: 50px;
            background: conic-gradient(blue 0deg 90deg, green 90deg 180deg, orange 180deg 360deg);
        }
    </style>
</head>
<body>
    <div id="grad"></div>
</body>
</html>