This is quite a common phenomenon: Sometimes when you are around new groups of people in terms of ethnicities/nationalities it might seem everyone looks the same at first. It can at times be embarrassing when you can’t tell individuals apart whom you have just met and talk to. That’s because you don’t know the people yet.
However as you get to know the people more and more over time you will likely find out differences between individuals. But it takes time and sometimes it takes effort.
The Domain for Truth 