I think it can get dodgy. I mean, on the one hand, dressing up in ethnic costumes like a Dutch girl or a in a kimono is fine (I hope, maybe that's changed recently) and I think it can be tricky to know exactly where to draw the line.
On the other hand, I can remember clear as day, going to the bathroom to get ready for the school Halloween parade when I was in 4th grade, opening the door and seeing a girl and her mom putting together her hair and make-up for her costume as an Asian girl. I was like, "Oh my gaw, she's being ME for Halloween!" There was an uncomfortable moment between all three of us and then we all went about our business. I never did reconcile how I felt about it or if my feelings were even terribly important since she wasn't being mocking or obviously disrespectful.
But, you could at least be historically accurate. And, always better safe than sorry.