Both simple design and the smokey colors point to Scandi and probably Sweden but there were so many small Swedish companies operating in the 50s and 60s you might find it hard to pin this one down. See previous inconclusive discussions about modern European jugs / pitchers. Having said this Ivo will probably come along now and say "It's XXXXXX"
I have about 50 companies noted for all of Scandinavia but the vast majority are Swedish. Bill Geary's book gives 56 for Sweden alone but that includes individual studio makers and more recently formed companies. Even in Ivo's very comprehensive A-Z Glass I cannot find Ronneby, Skansens, Trelleborg or Smalandshyttan. It could be that these companies were known by other names.
You do not mention the base, Anne. That would be interesting to know in any case and if a polished pontil then the Ebay favorite Holmegaard is a possibility. BUT, before I get shot down, I am NOT suggesting that all polished pontil pitchers of this type are Holmegaard or that Holmegaard always did a polished pontil. I just don't know.
At this point it could be taken as an indication of better than average quality, and another possible indicator of Scandi manufacture.