I like to think that DC's change from the shirt from the early days to the outfit he wears now is pretty symbolic to how much better he feels finally feeling love for the first time
Roll with me here
In the beginning I doubt his ex really let him have much autonomy. DC always dressed down because he felt like he didn't deserve to look like a fed, because to Bryan he was nothing but a toy that can be occasionally loved and put back on the shelf.
No matter how uncomfortable he felt with his arms exposed and dressed down, Bryan always made him feel lesser, which is why he looked more casual in the beginning.
Cut to when he finally leaves his ex and gets with the main five, suddenly the suits and ties come back. It's long sleeves, which makes him feel more comfortable, and he looks professional and crisp. Sure he doesn't know how to dress down, but his outfit reflected a change
The main five made DC feel important, that he was the fed, that he was the government. He finally had some of his autonomy back.
