Night mode for Slack Web
Installing a theme
You'll want to add this theme color to slack as well:
which I got from this site here: http://slackthemes.net/#/retro_monochrome_terminal
Instructions on how to add or customize slack themes can be found here
Adding the custom CSS above:
You'll need a chrome extension which allows you to write and persist custom CSS for a given website. I'm using stylebot for this. You can hit the
Edit CSS button when you're on the web version of the slack room you want to change and paste in the CSS below.