<<I know that their brewmaster is Weihenstephan-trained>>
My undergrad chemical engineering degree is from the Univ of Maryland, my M.S. in electrical engineering is from Wilkes, and my Ph.D. coursework in engineering at Oxford was great...but I did not stay the additional 3 years that Dissertaion work would have required; I spent 1983 as a Praktikant, an Apprentice in the bavarian breweries of Patrizier-Bräu AG, and have a Zeugnis document...I was learning in the labs of Weihenstephan only for three weeks of that year. SO I am not a Weihenstephaner.
<<Can you turn an almost all-pilsener grist into a beer with the color of a porter>> 10% of its grist is Crystal 150 malt, so the may is pretty brown/dark prior to decoction. As you may know, we are one of only a handful of breweries in the world that separates husk and adds it at the latter tun, so we can aggressively boil the mash at very high temperatures in decoction without evoking the terrible flavors that come out when one boils mash with husk aggressively. In the decoction boil of at least 60 min duration, the mash goes from dark to Black.
It is not a typical schwarzbier. Here's a discussion that offers insights on why I claim it is the world's first black pilsner, a Northern german Pilsner except for its color: