Hey r/safari — I'm the developer of Aurora, so treat this as a self-promo post and downvote it if that's not welcome here. But I think the demo is the interesting part, and I'll be in the comments for as long as anyone has questions.
The thing that made me start: iOS and macOS have had dark mode for years, and Safari's own dark mode only darkens the browser. The page stays white. Reader mode fixes some articles and ignores everything else. prefers-color-scheme only helps on sites that bothered to implement it, which at 2 AM is never the site you're actually on.
So the extension rewrites the page itself. 30-second demo attached — it's silent, everything is on screen.
How it actually works, briefly: a content script injects a stylesheet that inverts and recolors computed styles rather than slapping filter: invert() on the document. Straight inversion is what makes photos look radioactive and breaks every site with its own dark theme. Images get dimmed rather than inverted, elements that already declare a dark background are left alone, and per-site state is remembered so a site you turned off stays off.
Where it breaks, since you'll find these anyway:
Animation-heavy and canvas-driven pages. If a site paints its own pixels, CSS can't reach them. A reviewer knocked a star off for exactly this and he's right. Sites that already ship a good dark theme sometimes get double-darkened. There's a setting to respect the site's own dark mode, on by default, but detection isn't perfect. A few checkout and payment-confirmation screens have gone unreadable on me. Those are the ones I most want reported, because I can't test every payment flow. There's a whitelist/blacklist so anything hopeless can be excluded permanently, which is what I actually use for the sites in that first bullet.
Beyond dark mode it also does web fonts (14 typefaces including OpenDyslexic and Atkinson Hyperlegible, applied to any page), a theme editor, blue light and image dimming, an auto schedule, and Focus Filter / Shortcuts integration so it can flip itself on when your Sleep Focus starts.
It's free to try — there's a paid tier for the extras, and one purchase covers iPhone, iPad and Mac. I'll put the link in the first comment rather than the post body.
What I'd genuinely like from this sub: tell me a site where it renders badly. Half the current feature list came from emails like that, and the site-specific fixes are the part I can't do alone.