Page 9, Panel 2: the "villaness" character is described as:
"She's still very swarthy, and she's still glaring at me."
So... calling her "swarthy" means that she has dark Mediterranean or South East Asian skin.
And it's NOT always a compliment; it isn't one in this context, plainly.
I'm not certain that's what is meant to be conveyed, here; nor is having brown-ish skin usually considered a bad thing; just FYI, but the people who do dislike brown skin... well... let's just hope you're not one of them, yeah?
So, maybe... she's "smarmy," perhaps? (Meaning polite but insincere; like a suck-up)
Or perhaps she's troublesome? Boorish, obstreperous, perverse, or fussy?
Well, either way... saying "swarthy" as being a bad thing is not a good look.