Hi @olympesmn
It really depends on your theme and how you wish to adjust the background colour of the page.
One option would be to locate the themes header.php file.
You could then amend <body <?php body_class(); ?>> to <body <?php body_class(); ?> style="background-color:<?php the_field('background_color'); ?>">
Just as an idea/suggestion as this would save wrapping div tags around the page content.
