Is it possible to modify the window controls?

Hi there, I've been looking at yours theme and the Darcula theme, https://github.com/alecGraves/WolframNotebookDarculaTheme, and I wonder whether you can also modify the colors of the windows.
It seems that the author of https://gitlab.com/jakobneef/mathemeatica did it, but I don't really know how, so I'm letting you know of that and maybe you could find a way of extending your theme to the window controls!