Hi,
I think your source material could be to a specific type of glass ,which if related to Egermann as you suggest he was born in 1777 and known for his inventions in the 19th c of Lithyalin glass and coloured glazes for glass,
I can only agree with Antwerps comments above in that coloured glass has been made since glass was made , from the 16th c Venise produced coloured glass drinking vessels and other objects,Germany,the Low Contries and Bohemia were producing drinking vessels in coloured glass in the 17th c along with England and Ireland and have continued to make coloured glass to this day.
It might be helpful If you could clarify what you think was only available in Vienna till 1770s,
cheers
Peter.