Fedora Workstation 24 is shipping with the adwaita-qt theme that is a native Qt theme trying to blend with the Adwaita GTK theme. There's also the QGnomePlatform Qt platform plug-in that forces Qt applications to use this theme and the same font/icons as GNOME. In other words, it's trying to force Qt applications to look identical to their fellow GNOME/GTK applications.
In order to ensure that this adwaita-qt + QGnomePlatform setup is working well for the upcoming Fedora 24 release, they have setup a test day for tomorrow (17 March) to encourage developers and the ocmmunity to test out htis support.
If you are interested in participating in Thursday's test day or finding out more about testing the integration of Qt applications in Fedora Workstation, see this Fedora Project Wiki page.