Umbra

Umbra is an outstanding dark glassy theme designed for GNOME, taking inspiration from the Aqua and WMP themes, as well as incorporating a handful of the developer's own concepts. The theme is quite easy to install; simply right-click on your desktop and select Change Desktop Background, then click on the first tab, which is Theme. Next, drag and drop the theme's archive into the Appearance Preferences window. If your installation is successful, you will receive a confirmation message and can subsequently activate the theme by just clicking on it.

GNOME is a global undertaking aimed at creating a full desktop environment entirely based on free software. This initiative includes developing software development frameworks, choosing application software for the desktop, and working on programs tasked with managing application launching, file handling, and window and task management. GNOME is associated with the GNU Project, and it can be utilized with various Unix-like operating systems, such as Linux, as well as being part of the Java Desktop System in Solaris. The acronym, which originally stood for GNU Network Object Model Environment, is no longer in use. The GNOME project's emphasis is on simplicity, usability, and ensuring that everything just works.