The first decision is rarely aesthetic. The first decision is territorial.
Before you pick a palette — before you choose the mauve, the cream, the gold — you have to answer one question. The same question the playbook opens with, and the question almost no brand bothers to write down:
What is the space only this brand can own?
If you cannot answer it in a single sentence, the palette will do the work for you. And palettes, left to themselves, will always drift toward whatever the loudest feed in your niche already chose. That is how feeds end up looking like each other — not because anyone copied anyone, but because nobody claimed anything.
Claim the space. The palette follows.