David,
I followed this thread fully supporting your right to wear your kilt anywhere on board until you mentioned the type/color. While I can appreciate a guy in a kilt/skirt (whatever you want to call it), I think "cammo" anything would not be appropriate for formal night.
What if you were to compromise and get a "formal" kilt for the cruise? Get an authentic tarton complete with formal jacket like the picture with Sean Connery. Second to that I would say the black Utilikilt with a tuxedo shirt/jacket (or just the vest) would be the next best thing and probably would not be as controversial.
Just like any outfit, it's how it is put together. Yes, women can wear a skirt to formal night but there are some skirts that are best saved for shore excursions. A nice dark, pleated skirt would be better for dinner over the bright flowery short skirts worn during the day.
In any case, it is your vacation - be yourself and be comfortable. Wear your kilt with pride!