Compatability with thunderbird conversations

[ihasdapie]

Darko works great on stock thunderbird but breaks when using it with thunderbird conversations, which to my understanding does inject its own css and performs a lot of restyling. Would be nice if this extension could work with that as well, though I do understand that it is a fair bit of work.

Sadly this can't work. Addons cannot run inside another addons which seems to be this case.
The only way to make a dark mode in the "Thunderbird Conversations" addon is to re-implement it there. Which could be pretty simple considering all my addon does is inverts color and shifts hue.
Specifically all they need to add to make a simple dark mode is this:

@media not print {
  html:not(.no-darko) {
    filter: invert(100%) hue-rotate(190deg) !important;
    background: #2A2A2E !important;
  }
  html:not(.no-darko) img {
    filter: invert(100%) hue-rotate(-190deg) !important;
  }
}

[mherrmann3]

It could be possible using my alternative message-darkening solution that only uses userChrome.css and userContent.css: #8 (comment). Although I didn't try it for conversations (since I'm not using it), you would have to apply the filter also again within @-moz-document url(chrome://conversations/content/stub.xhtml) {, see silvercircle's userChrome.css