If you are a member of a minority "leadership group," playing the Victim Game for political and economic power, the object is to keep everyone off balance, so you will find that different terms become "offensive" at different times. It changes periodically, and there is no real rhyme or reason to it. When I was a kid, calling someone "black" instead of "Negro" got you in hot water where I lived.

There is absolutely no objective reason "Oriental" should be offensive, other than that members of certain small groups say that it is. In the dictionary, "Orient" is defined as "the countries of Asia, especially of eastern Asia." So basically, "Oriental" means "Asian." Yeah, I don't get it either. It's a hell of a lot better than the scientific term "Mongoloid," I tell you what.

If English is not your first language, you may have a lot of fun contemplating the difference between "people of color" and "colored people." One is acceptable, the other a rank insult.