In the daily build of Ubuntu 18.10 (Cosmic Cuttlefish) released today, the new Yaru (formerly known as Communitheme) theme is enabled by default. When the Ubuntu 18.04 LTS (Bionic Beaver) was released a few months ago, the Yaru theme has been developed, but now it is ready to become the default system theme for Ubuntu 18.10 (Cosmic Cuttlefish).
Driven by the community, Ubuntu 18.10 will introduce a new UI and experience that will make it more modern, accessible and glamorous. Yaru’s title bar, sidebar background and window colour, bright and elegant button settings provide warm and welcoming tones, providing a more discrete blue shade for text selection, rather than the intense orange colour used until now. There are also more rich notifications, as well as more profound depth effects, window shadows and borders, and GNOME Shell that looks similar to Unity 7 and Unity 8 designs.
Source, Image: omgubuntu