Android 6.0 Marshmallow will ship without the dark UI theme included in the early preview25
The original Android M developer preview gave us the option to swap the very bright colors of the UI to darker ones that were kinder to the eye at night. In fact, users could also set up the OS to transition between the bright theme at day and the dark theme at night. Sounds like a nice thing to have, right?
Unfortunately, after removing the dark theme in the second and third developer preview builds, Google has apparently decided to ship Android 6.0 Marshmallow without a dark theme option. Although the company has yet to address the issue in a formal statement, a recent discovery on the Google Issue Tracker shows that the feature will not be included in the M release.
Asked to bring back the Dark Theme in Android M, Google staff responded with a very straightforward comment: