Definition: Given a real-life anecdote of a complex ethical situation, generate a suitable title that describes the main event/root cause of the situation. Imagine that the given text is a social media post, and you have to write the title of the post, so the users can decide to read the main text or not.
Input: Obviously, English is not my first language, otherwise I would not be having this problem.
The town I'm studying in is predominantly white. However, there is a lot of international students at my university. To give you an idea: about 70% of the students in my masters program are international students. Since it's not a requirement for them to learn my language and the classes are in English, the only way we can communicate is in English.

I used to address every stranger in my language if they were white and in English if they where not. In like 95% of the cases, I was right about which language they spoke. A while back I addressed a non-white stranger in English, who got really offended that I assumed that he was foreign and didn't know the language, since he was a local. It got me thinking and I decided it might be a bit prejudiced, if not racist, of me to assume a not-white person is not local. So I tried to find a solution.

At first, I addressed everyone in English, independently of their appearance. In hindsight, that was a stupid idea. The person I offended would still be offended if I acted this way. Furthermore, I had some conversations with people in English where we both struggled to find the right words and only later realized we both had the same native language.

Since that didn't work, I started addressing everyone in my native language. This lead to a lot of confused  and nervous looks and I had to repeat myself a lot in English. I myself also get nervous if someone addresses me in a language I don't know, so I can imagine it's not fun for them either.

So since neither systems seem to work as well as my old one did and lead to a lot of confusion, WIBTA if I revert back to my old ways? If you think I would be TA, please let me know what you think I should do in this situation so I would not be.

basing my decision of in which language to address someone on their race/skin color