@soundofthunder Kvantum is for Qt applications. 
@Hanzel That information is long out of date. However, this is still true. Guess what I did for GNOME 47?
I adapted patches from Ubuntu, actually. Thing is, part of what they did depends on their Yaru theme. I haven’t yet figured out how to adapt to that.
@GoGRaDaN I didn’t know about that, thank you!
I’ve added support for changing the GDM accent color with accent-color-change as of r138.4f8caaf-2. It will present a Polkit prompt to apply it. I know that’s kind of awkward with a CLI application.
At some point, I may be able to make all this easier by including it in Layout Switcher. Stay tuned.