Meanwhile, we’re now seeing this dark blue background in the Google app on Android. It’s only appearing on one device running the latest beta (version 16.3.32).

The effect of web page text-background color combinations on retention and perceived readability, aesthetics, and behavioral intention (link) By Richard H. Hall and Patrick Hanna (An Americas ...

In order to move back to the dark blue background, the user can bring it back by going to Twitter's display settings and choosing Dim mode (instead of the inky black Lights Out or the bright Default).