Funny Purple Top on this Prevu sparkler

Not being the disco type, I was a little skeptical about the bottle of Prevu, when it arrived with a round, lavender top. I wanted to try it because I’m researching a BRANDY BOOK. And this sparkler is from Cognac, made with organic vodka, cognac, liqueurs of raspberry and black currant and blackberry — with a light violet aroma. Too highbrow? Too lowbrow?
I took it to Cape Cod at the end of the summer and we opened it before dinner. Usually, I get looks when I bring something to try. I get grilled, and people ask for little splashes to taste.
This time, I was bypassed completely. I poured tasting amounts in a few peoples’ glasses. When I went back for a second splash, the bottle was empty. I looked around: people were sipping happily. No one knew what it was, but the empty bottle said it all…