Mystique considers her for a second, frowning. Elphaba doesn't even blink at the joke, isn't phased by it in the least, and instead is staring at her, at her skin, like Raven might be contagious or something.

Or maybe that look means something else.

"It's a great ability to have," she says after a beat, casually. "'Cause in my world, if I'd been blue without it? I wouldn't have made it out of primary school alive."

She has no idea if there are other green people in Oz, but everything about Elphaba's mannerisms and body language say: outsider. It's a decent guess.