FYI, individual 'settlements' have not been academically equivalent to 'colonies' since the Hellenic age.  Greek foreign settlements were called colonies because the 'polity' at the time was widely understood to be a single city with its surrounding farm- and pastureland.  Since polities have grown to be defined by the geographical limits of their ability to project power over territory, usually including multiple 'settlements' or cities and towns, the difference between 'settlement' and 'colony' would be the exact corrolate of 'town' and 'state' (regardless of whether that state is a nation-state or a member-state like Alabama or Guadalajara).