change background color with user option
<form action="" method="post">
<select name="Color">
<option value="White">White</option>
<option value="Red">Red</option>
<option value="Green">Green</option>
<option value="Blue">Blue</option>
<option value="Pink">Pink</option>
<option value="Yellow">Yellow</option>
</select>
<input type="submit" name="submit" value="Get Selected Values" />
</form>
<?php
if(isset($_POST['submit'])){
$selected_val = $_POST['Color']; // Storing Selected Value In Variable
echo "<style>body{background-color:".$selected_val.";}</style>"; // Displaying Selected Value
}
?>