Instead of looking for an opposite, it's best to use more specific and respectful terms.
For example, instead of "oriental," you could use:
* Asian: This is a broad term encompassing a vast and diverse group of people from East, Southeast, and South Asia.
* East Asian: This refers to people from countries like China, Japan, Korea, and others.
* Southeast Asian: This refers to people from countries like Thailand, Vietnam, Indonesia, and others.
* South Asian: This refers to people from countries like India, Pakistan, Bangladesh, and others.
Ultimately, the best way to refer to someone is to use the term they identify with.
If you are unsure, it's always better to ask than to use potentially offensive language.