This is probably my favorite Picard-focused episode/arc. It’s incredibly rewarding from an emotional standpoint. And we get to see where Jean-Luc comes from, which gives us wonderful insight into his character and clothing choices. Why does Jean-Luc tend towards softly romantic peasant blouses and aristocratic hobbies? The answer is in his provincial childhood (and yes, Jean-Luc is totally a Belle).
The shirt he wears home is the same one he wore on his treasure hunt with Vash. I like to think it gives him confidence, or at least the same false confidence on display in this cap:
Once Chez Picard, he matches the scenery perfectly, which drives home that his aesthetic was honed in childhood as much as he may have run away from it at the time.
He and his nephew are dressed to match as René dreams of a life more like Jean-Luc’s than his father’s.
Jean-Luc’s second look, the green top and slightly more fitted pants, is more colorful and sophisticated. He outshines his friend with a job offer and his brother – until they get into a muddy brawl.
After which Jean-Luc and Robert are a mess, but a mess together. And having regained equilibrium he chooses to wear his uniform to depart.
Starfleet is Jean-Luc’s default. And here René is still dressed in a jumpsuit resembling the silhouette of a uniform, but colored to match his father. That’s a lovely costuming touch for this farewell. As are the flowers just behind Jean-Luc that subtly tie his uniform to the chateau visual.