If you need help with setting up Disqus in general, here’s a useful tutorial from How To Geek.
When configuring Disqus to work with Solaris, you’ll need to remove the word “comments” from the default output. In the Disqus admin, go to Admin > Settings (choose the appropriate account from the popup if you have more than one) > Appearance and look for the “Comment Count Link”. Configure it as below:
That’s it. Disqus now supports Dark mode as well.
Note: for Disqus 2012 users, there’s an extra step detailed here.