20th of May 2019
The author of ThemeEngine, Alex Zielenski has kindly given permission to me sharing the ThemeEngine application for macOS Mojave. Find it on the front page as it becomes available in a little while;
I have included a Xcode script that I have hacked together(with the help of an IRL friend that has coding expertise in an entirely different field than Swift. Thanks, Peter!) that allows the user, with Xcode installed, to create a colored backdrop for macOS Mojave based on the standard System colors that Apple has provided here:
I suggest that you read the Xcode project and type in the wanted color in place of the following:
layer.fillColor = NSColor.systemBlue.cgColor
With a change to "layer.fillColor = NSColor.systemGreen.cgColor" you'll get a green colored background for your Finder and Application backgrounds.
WHY AND HOW?