What's With The Blue Swimsuit?

I have been indulging in some Japanese porn lately. Some strange stuff there.

One thing I just don't get is the blue swimsuit thing. They get the female talent to disrobe and change into a blue (always blue) one piece swimsuit.
Then several men "molest" her while clipping away bits of the suit till she is wearing a sort of spandex harness exposing her privets . . .which are thoroughly dealt with.

As Jerry Seinfeld might have said, "So what's with the blue bathing suit?"

It's strange enough, but I think the Japanese and I have too different mentality to understand their ideas.

I have known a few Asians that wear the same blue one piece when the have come over to swim.