(WSJ) - I WAS WALKING through a wine shop recently when a wine in a blue bottle caught my eye. Had the winemaker—or, more likely, wine marketer—decided this disco-bright color was one that would draw buyers or did the contents require a colorful cover up? I spotted several other bottles of a similar hue—a few German Rieslings and a couple Moscatos—and wondered if I was seeing the start, the middle or the end of a trend. The larger question: How do bottle colors or grape varieties or even entire countries (see: New Zealand) become so...