@recnwpadmin It is not difficult to change that background of the wrapper using custom CSS code that you can add to Customizer > Additional CSS.
Here’s an example:
.page .entry-content {
background: #eee;
}
This will change it for all pages.
If you need it for a specific page, please provide more details or a link to your page.
Or you can even group all blocks on that page in a Group block and add the background color in the Styles setting.
I’d appreciate it if you could change your review to 5 stars if this solution was helpful.