How to create One Page

Heloo,
I tried to create a one page and show all pages on this page like this:
Theme Link

i found this code:

<?php $pages = get_pages();
foreach ($pages as $page_data) {
    $content = apply_filters('the_content', $page_data->post_content);
    $title = $page_data->post_title;
	$slug = $page_data->post_name;
   	echo "<div class='$slug'>";
	echo "<h2>$title</h2>";
	echo $content;
	echo "</div>";
}
?>

Also i created two pages with style-sheet for each page background: #399 and the other page #F96 as .page1 .page2

everything working fine but without the styles.

I know maybe this is the wrong way to do that I don’t have enough experience in wordpress codes and i checked codex but my english not good to understand everything.
So please can you help me with that or is there any plugin can do this i mean like sections on one page?

thanks alot