Install eog-plugin-fullscreen-background by entering the following commands in the terminal:
sudo apt update sudo apt install eog-plugin-fullscreen-background
Description:
Fullscreen Background plugin for GNOME Image Viewer
eog-plugins contain a set of plugins for eog, the GNOME Image Viewer. . This plugin enables changing the background color for fullscreen mode.
Homepage: https://wiki.gnome.org/Apps/EyeOfGnome/Plugins
Version: 3.26.2-1
Section: universe/gnome