In a rare event, Apple has rolled out substantial updates to the web-based iCloud interface meant to allow users to access Apple services like Mail and Photos when they’re away from a Mac, iPad, or iPhone.
The flagship addition is dark mode; it “will automatically match your device settings with a Light Mode or Dark Mode color scheme,” Apple explains as part of the update.
There is also now a way to customize the background for the iCloud web interface—specifically, you can choose between several colors.
https://arstechnica.com/gadgets/2024/10/apple-adds-dark-mode-and-other-features-to-icloud-com/