Collosians 1:15= The FIRSTBORN of all creation= created.
Refers to pre-eminence over all creation
for
Colossians 1:16 (LEB) — 16 because all things in the heavens and on the earth were created by him, things visible and things invisible, whether thrones or dominions or rulers or powers, all things were created through him and for him,
he created everything thus had to be himself uncreated
To also be noted firstborn is not first created
Exodus 4:22 (LEB) — 22 And you must say to Pharaoh, ‘Thus says Yahweh, “Israel is my son, my firstborn.”
Was Israel the first created thing
1 Chronicles 5:1 (LEB) — 1 The sons of Reuben the firstborn of Israel (for he was the firstborn, but when he defiled the couch of his father, his birthright was given to the sons of Joseph, the son of Israel, so that he was not enrolled in the genealogy as the firstborn,
Reuben was removed from his position as the firstborn
Jeremiah 31:9 (LEB) — 9 With weeping they will come, and with pleas for mercy I will bring them; I will let them walk by streams of water in a straight path. They will not stumble in it, for I have become to Israel a father, and Ephraim, he is my firstborn.”
Or was Ephraim the first created of God
Your understanding of the term is defective