It looks like they are adding options to choose from different styles. I don't see the link yet in my account settings but this screenshot makes me think it's coming to everyone. https://twitter.com/jublonet/status/830131346798424064
The author of that tweet added a follow-up that it's not a real screenshot, just a mockup.
I use Stylish on Safari and Chrome with both the GitHub Dark and Hacker News Dark themes. My eyes couldn't be happier.
For anyone considering using stylish on chrome, you should know that the latest update turned on tracking by default. It will send your current url to fetch a list of "styles for this url", but does it even when the popup isn't visible. You can check by looking at the network tab of the `background.js`.