Android fans were given a glimmer of hope when a Google Issue Tracker thread — which was initially started back in November 2017 — requested a dark mode for Android 9.0. After months of inactivity, the issue was marked as “fixed”. Android users were further stoked by a Google team member that said the feature would be “available in a future Android release.”
But before you start breaking out the champagne to celebrate the impending arrival of a system-wide dark mode in Android 9.0 (Android P), Google says that any previous comments regarding dark mode were made by mistake.
"Unfortunately, this bug was closed prematurely due to a miscommunication with the team that handles AOSP issues," said Google in statement to Android Police. "What we *have* added in a future Android release is a developer-facing setting (via Developer Options) to toggle the -night UI mode qualifier, which will make it easier for developers to create and test apps that implement night mode."
In other words, app developers will be able to [better] implement the functionality in their own apps, but a system-wide toggle for dark mode isn't in the cards for Android P. However, we're still holding out hope for its arrival with Android Q in 2019...