Here's what they look like:
The team has been inching in this direction for a while now, ever since the now home jerseys were introduced to almost universal praise for how sharp they looked as alternate jerseys for the 2014-15 season. They made those jerseys the ones they wore at home throughout the 2016 playoffs and the team store has been de-emphasizing the old "Vegas gold" stock and really pushing the traditional black and yellow. Now the team is full-time back to black/yellow/white, and I expect to see a similarly happy response to unveiling these full-time.
Ironically enough, the team ditched this jersey and color scheme after winning their second straight Stanley Cup in 1992, so it's perhaps only fitting that they go back to this jersey while they will be defending Cup champions. And it's also fitting that the Vegas gold away jersey also goes out a winner, since the last time it was worn the Pens skated the Cup in San Jose.
For a further look at the history, design and rankings of all the Penguins jerseys throughout the team's 50 year history, check back with this Pensburgh article from 2014 that a graphic designer guest wrote for us.