If you're a Telegram user (hi), then you'll understand how cool this latest news is. The privacy-focused messaging service is finally getting custom theme support on Android, which is just fantastic. You have three basic ones to start, and one of those is a dark theme.
Other than that, you get the standard default theme — you know, the one we've all been staring at for a while. The final one is blue, which feels slightly redundant, but I think that it looks quite nice. The default backgrounds match the theme headers nicely, but you can still have the other image backdrops if you feel so inclined.
In addition to that, Telegram now comes with a theme editor in the app to create your own look (which was also recently added to the desktop version). You can also visit the @Themes channel to take a look at what other users have come up with. Personally, I am liking the Holo/Tron feel to the new dark theme, so I'll probably stick with that for now (though, a darker Hangouts look would be cool, too).
The blog post claims that most Android users should have this by now, but if you happen to be missing out, you can grab the latest update from APKMirror. iOS will be getting the update in the coming weeks, too.