AppStudio 8 brings Dark Mode support to your apps. To enable it, go into Project Properties and set backgroundColor to inherit.
Read more here:
https://blog.appstudio.dev/2020/01/appstudio-8-dark-mode/
A colleague of mine and me joke about Dark Mode v.s. Light Mode.
I have found that people who like Dark Mode - are often younger people who don’t remember Dark Mode from - mainframe terminal days. 
In the olden days, everything was “Dark Mode” - a black screen with green or yellow monochrome, or, various colored characters. At my first job - at IBM - you Stepped Up when they let you trade a green monitor for a color monitor.
Eventually, many of the people who logged all that time on those black screens learned that a color scheme closer to Paper is easier on the eyes. Thus a white/light background with dark characters.
So all you young whippersnappers with great eyes - enjoy Dark Mode.