Which color setting is for "best answer"?

Took a look at your community, it looks like it’s coming from a CSS variable called .post--bestanswer{}

I have no idea where to set that either on the front-end. What you can probably do is add custom CSS to update those values for now:

.post--bestanswer {
    border: 1px solid ***ADD COLOR HERE***;
    background: ***ADD COLOR HERE***;
}

Ahh, that makes sense. Thank you!

Apparently this is a bug that is currently being fixed. The expected behaviour is that the success color is being used for the best answer (the comment itself as well as the pinned solution under the question). But right now some other color is being used instead.

In the meantime you can use Custom CSS to override the wrong color, like @mstone suggested. I recommend to also include the pinned solution, so the Custom CSS would look like this (Source: @Yoeri)

.post--bestanswer, .answer-field{
  background: #00d89e;
}

Thanks for jumping in Bjorn, you are right!