A developed country is a country where foreigners are immigrants, are the poorest, are the exploited and mistreated ones.
A poor country is a country where foreigners have higher social status than the locals, are called expatriates, are wealthier, and date the nicest girls while exploiting the locals.
If you are poorer than foreigners in your country, your country is colonised.
If as a foreigner, you are richer than the locals, you are certainly part of a colonial enterprise, and happy helping colonize the locals.