Depending on how many you have I would go with custom post types. But if you only have a few You could create triggers for conditional CSS.
Save a custom field on your post like this:
background => green
Then on post template:
// echo the string "green"
<div class="" style="<?php echo get_post_meta( $post_id, background, true ); ?>" ></div>
Or you could create a custom class to style your stylsheet for your super special post:
.awesomepost{ bunchastuff:amazing; }
Then in your post custom field create
stylefiftythree => awesomepost
and in the div you want to add the class to echo the awesome post within the class attribute.
<div class="<?php echo get_post_meta( $post_id, stylefiftythree, true ); ?>" style="" ></div>
After coding this I realize this is terrible. Keeping track of these pages and their styles alone is terrific. You have to go with CPT's or Page templates unless you have like under 10 of these scenarios.