Thank you for reading this and your response. I had stopped responding to this post because I have been unable to respond to new comments without scrolling through all the old ones, but I wanted to answer your question.
A White passing person = people who are biracial and go live as a White person without being detected (i.e. Jewish people, some Black people, other people mixed with European ancestry with very light skin and straight/curly hair that allows them to pass as a White person). Many people of color pass a White although they are not (i.e. White Cubans). Additionally in America, there are people of color who are allowed to be White (i.e. East Asians). America includes them in the White category and they also live and discriminate like White people.
White is complicated. Good question though. Thanks for asking. I hope this helps. You can do a little googling and there are all sort of subject on those who pass as White. The list of people trying to avoid Blackness and all the misery that comes with it is long (lol).