[SedVictaCatoni]

For almost 700 years, Egypt was a Roman colony (first of Rome, then Constantinople).

Well, no, it wasn't a Roman colony, because the Romans never sent anyone to settle there and populate the place. Considering that at the time of the Battle of Actium, Alexandria was a larger and much more economically important place than Rome, the idea that it needed to be colonized would have been considered absurd.

Egypt was, instead, initially an imperial province - essentially a miniature nation-state administered by the Emperor's agent for his personal benefit, instead of being under the control of the Senate.

[Eternal_Bear]

"Well, no, it wasn't a Roman colony, because the Romans never sent anyone to settle there and populate the place"

What about Antinoopolis founded by Hadrian? There may have been other Roman colonies in Egypt.