I agree that we can safely put this down as ZBS. According to Mark Hill in his book Hi Sklo, Low Sklo, Klinger designed for ZBS from 1948 onwards to 1982, many of his vases were produced for decades, and that his designs are hard to date because of that. If someone happens to know whether this particular colour was introduced at a certain time, we can put the date after that, but other than that, I have no clue.
Astrid