: There is ongoing discussion regarding compiling FileZilla against newer versions of wxWidgets (e.g., version 3.3), which would provide native dark mode support for Win32 apps. PapirusDevelopmentTeam/papirus-filezilla-themes - GitHub
In response to user demand, the FileZilla team introduced a hidden theming engine in the 2025-2026 update cycle. Here is the official way to activate the closest thing to a dark theme: filezilla dark theme upd
FileZilla, one of the most popular FTP clients, has finally introduced an official dark theme. No more eye strain during late-night file transfers. This update brings a modern, fully dark interface that matches your OS preference or can be manually enabled. : There is ongoing discussion regarding compiling FileZilla