“This week in Plasma” brings wallpapers that transition from light (during the day) to dark (when the sun goes down), better search results in Discover, visual polish for the Audio Volume widget, and tons of other stuff!
https://blogs.kde.org/2025/05/24/this-week-in-plasma-time-of-day-wallpapers/
I have been using koi and it has worked well so far.
https://github.com/baduhai/Koi