I always used to have a restful vertical gradient on my background - like a watercolour wash.
Now this option is gone from the GUI. I am offered various hippos, or the suggestion that I might like to create a gradient using an image editing tool and save it as a jpg or some bollocks like that.
Luckily the Gsesttings tool allows me to do what I want;
gsettings set org.gnome.desktop.background primary-color "#8057D8"
gsettings set org.gnome.desktop.background secondary-color "#E5A28E"
gsettings set org.gnome.desktop.background color-shading-type "vertical"
Stitch that, hippo.