A person from Colombia is...
Colombian
A person from the UK is...
British
A person from Peru is...
Peruvian
A person from Korea is...
Korean
A person from the US is...
American
A person from Japan is...
Japanese
A person from Argentina is...
Argentinian/ Argentine
A person from Canada is...
Canadian.
A person from Germany is...
German
A person from Ireland is...
Irish
A person from Mexico is...
Mexican
A person from China is...
Chinese