I successfully compiled the style and tried to apply it to the latest version of VirtualBox but it doesn't take the style.

I have a Fedora 42 Linux workstation (kernel 6.17.4) running Plasma 6.4.5 /Wayland. I am using VB 7.2.2 with a W10 guest and guest additions 7.2.2 r170484 added. Everything seems to be set-up ...