It's a mess. First, why or how in the world did I lose my background color. The template preview of my Custom template shows the page background I want and originally had.
Somehow it changed to light blue which is matching the margin area closely. 
When I click preview, not the template preview as in that step, it shows the wrong background color as described.  How do I get the page background to where it shows in the on the right in the template preview and to stay there.

Will that background remain from page to page unless there are pages where I want it differently.

How come the option to SAVE is often grayed out and I have to back out of what I'm doing and come back in order to save.