Excessive transparency of Qt applications in Gnome44

Fedora 38, GNOME44, AMD video. In Qt applications such as Strawberry, I get a transparent menus like here (screenshot). As you can see, it’s too transparent and the menu is almost unreadable.
I can’t find where I control it and make such menus more readable…

Dolphin: oc-ssr_20230920_123959|690x388