Facebook has recently launched a dark mode for its Messenger users. The new dark mode feature is now available but to use it you need to activate it by sending a moon emoji.
The trick was spotted by Android Police, 9to5Mac, and others, to activate it send someone or yourself a crescent moon emoji. Once you do so, a shower of moons appears in the chat window, and you will get a prompt to activate the dark mode in settings. Go to your profile page in the app, and it will give you an option to turn the mode on.
According to Android Police the new mode is now rolling out but is not available to everyone, and that some have gotten a message saying that it’s still a work in progress.