Appropriate

Yesterday in the German language class, one of the topics was how to pay compliment to others. What could be my feeling for that? To a person who hates daily-drama extremely like me, one can certainly imaging how horrible it was.
"Oh my God!" that was exactly what I thought and felt by then.
I cannot help to say that westerners are really stupid enough. How could they treat such superficial staff as part of their communication training seriously? No wonder such society need elite, deadly, while the populace are too mideocre.
When it was my turn, I exclamated to the classmate sat next to me, 'oh, is your hair-color natural? it's sooooooo beautiful!'
Certainly, the teacher told me that it was not appropriate.