In the upcoming Ep 7 movie, General Hux wears a collar on both his tunic and his coat, they bother me so I went digging because Star Wars generally has nehru-style collars if any at all except for Lando, and what I found was that Lando seems to be the only one that has a traditional collar.
In ESB, his cape has a collar:
At the end of the film, his shirt has a collar:
In ROTJ, as a general, his uniform had a collar:
This was obviously intentional, Lando is the only character of note which I can think of that wears one, it's a style choice on the part of the costume designer. So what does it say about the character, what about collars makes them so special about the storytelling that every other significant character's costume doesn't have them, and what about Lando is so unique that they designed his costumes to break that?