It is weird, but there is a lot of racism built into these words. If a Filipina goes to work as house-maid in Saudi Arabia, technically she is an expat, but no one is likely to call her that. She would likely be labeled a migrant or immigrant. If that same woman is a nurse, she is still likely to not be called an expat by westerners. There are certainly some double standards because a white begpacker from the USA can go live in Cambodia in poverty for a year, but still be considered an expat before being referred to as a migrant or immigrant.

Skin color certainly has a lot to do with how you'll likely be labeled by westerners living abroad. Just food for thought is all.