index.html

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Bootstrap Color Block</title>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.2.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-rbsA2VBKQhggwzxH7pPCaAqO46MgnOM80zW1RWuH61DGLwZJEdK2Kadq2F9CUG65" crossorigin="anonymous">
  <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.2.3/dist/js/bootstrap.bundle.min.js" integrity="sha384-kenU1KFdBIe4zVF0s0G1M5b4hcpxyD9F7jL+jjXkk+Q2h455rYXK/7HAuoJl+0I4" crossorigin="anonymous"></script>
  <link rel="stylesheet" href="style.css">
</head>
<body class="d-flex flex-column min-vh-100">

<div class="grey-background">
  <div class="container colorblocktop">
    <h1>Bootstrap Color Block</h1>
    <p>Welcome to a sample page using Bootstrap.</p>
  </div>
</div>

<div class="white-background">
  <div class="container colorblocktop">
    <h1>Bootstrap Color Block</h1>
    <p>Welcome to a sample page using Bootstrap.</p>
  </div>
</div>

<div class="black-background">
  <div class="container colorblocktop">
    <h1 style="color: whitesmoke">Bootstrap Color Block</h1>
    <p>Welcome to a sample page using Bootstrap.</p>
  </div>
</div>

<div class="grad-background">
  <div class="container colorblocktop">
    <h1 style="color: whitesmoke">Bootstrap Color Block</h1>
    <p>Welcome to a sample page using Bootstrap.</p>
  </div>
</div>
</body>
</html>