demo.html

<html>
<head>
    <style>
        body {overflow: hidden; margin: 0; padding: 0}
    </style>
</head>
<body>
    <canvas></canvas>
    <script src="simplex_noise_2d.min.js"></script>
    <script>
        const canvas = document.querySelector("canvas");
        const ctx = canvas.getContext("2d");

        const width = canvas.width = window.innerWidth;
        const height = canvas.height = window.innerHeight;
        const size = width / 256;
        const pixels = 2 / 150;

        s(1337);

        for (let y = 0; y < 2; y += pixels / 2) {
            for (let x = 0; x < 2; x += pixels / 2) {
                ctx.fillStyle = `hsl(${parseInt(b(x, y, 8, 1, 4, 0.5, 2.0) * 250)}, 50%, 50%)`;
                ctx.fillRect(x / 2 * canvas.width, y / 2 * canvas.width, size, size);
            }
        }
    </script>
</body>
</html>