Where can I find the main explorer background color? I've looked forever and can't find it.
You have to change the various parts in shellstyle.dll. See
http://http://zeusosx.deviantart.com/art/Black-background-white-text-81934667 to change the background color of the explorer list view.
To change the background color of the folder tree, search for:
<ProperTreeHost
in the shellstyle.dll UIFILE, scroll down a few lines until you find:
background="themeable(argb(255, 252, 252, 252), window)"
and change the last three values to change the folder tree background color. For example, to make the background black, change the values to:
background="themeable(argb(255, 0, 0, 0), window)"