In various incarnations of Star Trek, we observe the Federation founding and maintaining numerous colony worlds. These worlds are typically (though not exclusively) inhabited by humans, have a relatively low population (for example, New Providence had less than a thousand inhabitants), and typically serve as remote flashpoints or otherwise exist to portray a "frontier"-like atmosphere without technically leaving friendly space.
On the other hand, we see various worlds in various stages along the path to full member-world status in the United Federation of Planets (UFP). What I noticed about these candidates, however, is that they are the homeworlds of civilizations, such as Bajor and the homeworld of the Evora, not previous Federation colony worlds that have expanded beyond "colony" status.
Can a Federation colony gain full member world status in the UFP, or is membership only granted to the homeworlds of civilizations (with colonies, presumably, remaining under the jurisdiction of the founding member's government or the entire UFP government)?
Mentally, it is easy to compare the UFP with modern-day nations with a Federal political structure such as the USA and Canada which have followed the general model of admitting former territories to full membership upon reaching designated population, economic, or political goals, but it is not clear if the analogy is meant to go that far.