Ubuntu 20.04 change background to solid colour

Newer versions of Ubuntu Desktop have removed the capability to set the background to a solid color. You may run the following command in a terminal window to accomplish this task:

To clear the current image setting:

gsettings set org.gnome.desktop.background picture-uri ""

To set the primary color (the first color in a gradient or the solid color):

gsettings set org.gnome.desktop.background primary-color '#000000'

Reference: https://www.fcpace.com/node/55