Here we have clothing Jean-Luc wears while engaging in various hobbies.
As such they have certain parameters related to what participants wear, particularly for the athletic activities. Here’s what fencers for the Rio Olympics:
It’s basically the same – if anything now is more futuristic than TNG’s version. And the unitard Jean-Luc wears to play racquetball could be purchased off the rack in 1990, and most likely was.
Horseback riding allows for slightly more individual flair, which Jean-Luc absolutely engages with. While maintaining the ‘uniform’ of English Riding, he wears a wrap blouse in “Starship Mine” and his jacket in “Pen-Pals” is not unlike his alternative Captain uniform debuted in “Darmok”.
As for the painting scene, his shirt is either the same cut as the one in “Starship Mine” or is the same shirt in different lighting.
In both fashion and fancy, Jean-Luc knows what he likes – or to delve even deeper into his psyche, what looks good on him and fits the persona he wants to project. Fencing, riding, painting, and arguably racquetball, are the activities of an aristocrat. And it is interesting that he chooses a softer, more romantic look when performing them (as opposed to the street level aesthetic he goes for when playing out hero fantasies). It’s also fun that in “Starship Mine” he ends up playing out a street level hero fantasy while dressed in his more romantic, aristocratic aesthetic.