Thank you all so much for your feedback. I know it's standard in fanfiction to slip in canon quotes without using anything to distinguish, it works well and I don't fault the community or other authors for doing that. However, I still can't bring myself to do it. I don't think I could look my students in the eye when discussing proper citations if I did so. Sorry if I'm too fastidious.
Given your feedback, I think what I'll do is add an author's note at the beginning along the lines of: "Based on characters and plot from
Persuasion by Jane Austen and
North and South by Elizabeth Cleghorn Gaskell, with influences from the BBC miniseries of
North and South. Text from Jane Austen is in
purple. Text from Elizabeth Gaskell is in
blue. Text from the miniseries is in
green. The tense, pronouns, or wording of these quotes may be slightly modified to fit the scene."
That way the new font color will be darker, more subtle, easier to read, and the colored portions won't be broken up for slight modifications of tense or pronouns (which is just as obnoxious to do html tags for as it is to read).
I'm
almost done with the
Persuasion/N&S crossover. I've just got to finish the last chapter (or two?) and epilogue.