I'm going to be taking a cruise in January and we'll be having both a formal and semi-formal night for dinner. I decided that the occasion calls for the kilt to be worn.

Space being an issue, I thought that instead of taking both a PC (for the formal) and a day-jacket (for the semi-formal), a black Argyll would suit for both, just dressing up a bit more for the formal, and down a bit for the semi-formal.

I was wondering if black cloth buttons would be appropriate on an Argyll to tone it down a bit? Or would it make it too somber?

And, if black buttons were appropriate, where can I get them?

BTW, the cruise website isn't terribly helpful on what exactly semi-formal means. I've heard it can be a suit or tux, or much more informal such as a dress shirt without a tie and jacket. I opted to go the more dressy route.