We’re all patiently waiting for Slack to introduce Dark Mode for its Mac app. Meanwhile though, Sblack is an interesting app if you’re looking for a way to have dark mode in a native Slack App.
The challenge with 3rd party dark mode support is that it constantly has to adjust to the HTML and CSS changes of the host DOM. I’m noticing that recent threaded replies have lost whatever customization they used to have, for instance. Little broken details like this keep someone like me from being able to use this, but your mileage will vary. It’s worth checking out.