It appears to be the technical term for glass, which isn´t perfectly clear, but has the typical tinge of e.g. recycled glass. So it should have the typical greenish tinge to it.
Thank you; that fits. glas-freital.com isn't responding, but the wayback machine has the pages: they list three colors for their 750 ml Bordeaux Allegee BM:
weiß,
halbweiß and
lichtgrün.
In german sometimes the term ´weiß´ (white) is used synonymically with ´klar´ (clear).
Would there be a distinction between
klar and
krystall, i.e. degree of clarity? I'm inclined to think this is just more marketing.
In the insulator world, when they wanted a colorless glass, and used "glassmaker's soap" (manganese dioxide) instead of expensive and rare pure silica sand, they ended up with what collectors call "off-clear": colorless, but not really clear, since the manganese added a purple tint which just countered the greenish tint caused by iron contamination (and both tints were subtractive). Off-clear is sort of very light gray, if you can picture that in glass (a couple examples attached).