Dark theme with NO bright lines or letters on the screen?

How do I get a browser theme that is dark, with text and ALL lines, outlines, icons, everything being not bright? Not a super white or any super bright color? Because I try different themes, like high contrast themes, when I am writing in the dark at night but there are always elements of the screen (like lines around buttons, for example) that are still distractingly bright. I can practically read in the dark so this brightness is eye-squinting to me.

You could keep looking for a different theme as I know that a lot of people seem to like darker themes, myself included, so there’s likely some available that would fit with what you’re looking for. Or, if you wanted, you could create one yourself with Firefox Color as it gives you more customization than a regular Theme submission does. And with Firefox Color you wouldn’t even need to upload the theme to use it unless you wanted to share it.