Brazil is mixed and has lots of white people too, so it wouldnt work as well as you expect, except maybe in the Northeast and North regions, as those have less white, though they are still mixed.
Honestly you would have more success leveraging your status as an american or europesn foreigner over your white race. People here worship americans and europeans, see them as coming from better lands and being more cultured.
However, I must warn you: you need to at least speak and understand portuguese, even with a heavu accent. People here are overwhelmingly monolingual and dont speak foreign languages, even english. So you wouldnt have much success if you couldnt understand people and they couldnt understand you.