wallpaper – How to get a .png of the desktop background "color"

In the Ubuntu 16.04 settings, you can select a normal color as the desktop background under Appearance> Colors & Gradients>. I like the color selection from 16.04 and want to use the same color on the Ubuntu 18.04 desktop background, but 18.04 does not offer the same color.

Is there a way to save a Ubuntu Desktop color background .png file at 16.04 so I can use a .png file of that color for 18.04?