Dark transparent background in Acquia_Slate

1. I would like the dark transparent background to only be as tall as the "Seascape Banner" behind it.... and have the Seascape Banner grow or srink to fit the content of the Preface Top region.

2. I've only been able to make that background appear by making a change to local-css even though all the banner backgrounds are in the style.css file. How to make them all available?

3. I'd like to control whether the background in Preface/Top appears on first page or in others. Right now it seems to be in all pages.

I am using Fusion/Acquia 6.x 2.x and Skinr 1.5.