https://thenextweb.com/apps/2018/07/30/youtubes-android-app-is-finally-getting-a-dark-theme/

Although YouTube has offered a dark theme on its web and iOS apps for months, it’s been taking its own sweet time bringing it to Android for some reason (seriously, what’s the hold-up?). Now, there’s hope.

Redditor u/Absinth92 reported on the weekend that the option had become available on his mobile device – and Android Police reports that others have spotted the feature too.