BigBusiness uses System Colors, which means large swaths of grey or gray prevail.
People may prefer a background with super contrast for better legiblity or mood effect.

Background File is a setting in My Prefs that lets you select an image for a background.

Pictured is Light-Marble which automatically switches to Dark-Marble in Dark Mode.

This feature is for testing and works with Compact window and the latest Client, first.
Now, it appears to work throughout but let support@bigbusiness.com know if not so.

Unicorns is a Background File choice in My Prefs that changes Big Business windows.

Metal is a Background File choice in My Prefs that changes Big Business windows.

Marble is a Background File choice in My Prefs that changes Big Business windows.

Hue is a Background File choice in My Prefs that changes Big Business windows.

Parchment is a Background File choice in My Prefs that changes Big Business windows.

Gold is a Background File choice in My Prefs that changes Big Business windows.

Bubbles is a Background File choice in My Prefs that changes Big Business windows.

Bayou is a Background File choice in My Prefs that changes Big Business windows.

Binder is a Background File choice in My Prefs that changes Big Business windows.

Foil is a Background File choice in My Prefs that changes Big Business windows.

Grid is a Background File choice in My Prefs that changes Big Business windows.

Pastel is a Background File choice in My Prefs that changes Big Business windows.

Patterned is a Background File choice in My Prefs that changes Big Business windows.

Splotch is a Background File choice in My Prefs that changes Big Business windows.

Swirl is a Background File choice in My Prefs that changes Big Business windows.

White is a Background File choice in My Prefs that changes Big Business windows.