For users switching from Microsoft Windows, there’s now a new Linux Distribution with default theme looks like Windows 10 and/or Windows 11.
It’s Wubuntu (Windows Ubuntu), based on Ubuntu.
It so far includes 2 versions based on Ubuntu 22.04 LTS. One with Windows 11 theme on KDE Plasma 5 desktop, and another with Windows 10 theme on Cinnamon desktop.
This simple tutorial shows how to install and use Kvantum theme engine to change themes for your Qt5 and Qt6 applications in Ubuntu 20.04 and Ubuntu 23.10.
GNOME Desktop uses GTK toolkit for its applications and KDE/LxQt uses Qt toolkit instead. These apps work on each other desktop environment, but may NOT look native.
To unify the look and feel, Fedora Qt developer team has QGnomePlatform, adwaita-qt, and QAdwaitaDecorations projects to make Qt apps look better in GNOME. So far, only QAdwaitaDecorations is in active development for implementing Adwaita-like window header and border for Qt apps.
For Qt app window color, buttons, and other components, Kvantum is good choice to do the job.