Yeah, I wouldn't make too much of an issue of the whole gringo thing. People will just come off as a whiney. It's just an expression. Thankfully in spanish, things haven't gotten so ridiculously PC like they have in english where even a passing reference to someone's ethnicity is considered insulting.
the reason political correctness exists is because in the past people wouldn't make allusion to someone's ethnicity in passing. so i'm ok with that.