You know perfectly well Hacker news is the apex of efficiency and minimalism, and that "good hackers" don't care about trivial nonsense like "accessibility" or "readability" or "user experience," only the purity of signal over noise.
Now go to the blackboard and reverse binary trees until you've learned your lesson.
Considering the site uses a bunch of CSS classes that end up always using the same visual style (e.g. black text), i'd say that "good hackers" can use Stylus or some other similar addon and customize the site's look.
You can do a lot of customization with it, while overall my HN looks 90% the same as the default style (since i don't dislike it), i have done some customizations like making every other comment have a slightly darker background (to easily distinguish them when scrolling) and added some color to distinguish different parts of each post.
You don't even need to be a "good hacker". Just go into browser settings, set your preferred colors, and set it to disallow sites from setting their own colors (mobile browsers seem to have removed this functionality for some reason, but desktop ones still have it).
Now go to the blackboard and reverse binary trees until you've learned your lesson.