On the page / post admin interface. on the PageLines Meta Settings it will be nice, on the background section to have also the option to choose a different color for background of that page.
It will create colorfull websites.
For example, the user can upload a semitransparent background noise / pattern image and choosing a different color for background of the page the user will create a website that will inspire, make it relate to their national flag, make it available for children by making them guess the background color to educate, make the user sink deeper, like creating an ocean floor website, from light blue to dark blue if the user chooses the menu items in order like page 1, then page 2 and so...
There are so many things a different color per page can be that easily selected without further css setup from the user.