The default layout view background color is white, but you may find that black provides a better contrast. You can customize your layout view colors using the Options dialog box.

I figured I'd give the new layout a few days. On desktop I found an option to change the layout to list view which somewhat minimized the massive amounts of wasted real estate the new layout had.

If you notice Outlook's layout change out of the blue, it may be because you unknowingly messed with the view option in the menu. There are two other premade views you can find in Outlook aside ...