Some Qt5 applications don't use a Gtk+ style by default in Gnome (in Ubuntu 18.04 for example), which makes them look out of place. This includes applications like VirtualBox, VLC, qBittorrent, Simple Screen Recoder, the ownCloud desktop client, and so on. This article explains how to fix this and get Qt5 applications to use a Gtk+ 2 style in Ubuntu.
Some of the products that appear on this site are from companies from which QuinStreet receives compensation. This compensation may impact how and where products appear on this site including, for example, the order in which they appear. QuinStreet does not include all companies or all types of products available in the marketplace.