Well, if you have three buckles on your kilt, that lower one is going to be a problem, and so will the strap color unless you have a daywear kilt with brown straps and brass buckles. That could never be worn as evening wear, so you will have to have a second kilt that has black straps and silver buckles. You could always lop off the lower buckle and strap, but then it would look like you don't have the lower buckle and strap on your kilt... because you don't.
I'm just joking, but I'm sure there are people who would notice all that.
It would be interesting if someone came up with a buckle set that had removable center pins, I'm not sure of the term, that would allow for a buckle to be changed on the kilt without involving a knife. I guess the lower strap would also need to be removable/exchangeable.