I've tried it just a few hours ago, at the moment it's my goto alternative, cheers! The only downside to your extension is that I can't regulate the visual contrast, so some text, like HN content text, is a bit too glaringly bright.

Also, I'm not sure why, but the monospace text in the HN reply box is quite unpleasant to read when inverted.

But good effort! Is it open source?