There definitely were frosted glass versions of the Bagley Carnival pattern, so if you keep looking you should find one (probably on ebay). The Carnival pattern was made in a wide range of items including a fruit set, biscuit barrel, butter dish, cheese dish, sugar and creamer, and celery vase. The catalogue number is 3141 and the registration number for this pattern was 849118 (November 1946). Pieces have been found with the wrong registration number.
In the 1953 Bagley catalogue the Carnival vase (which was called a Celery Vase to avoid taxes) was offered in all the Bagley colours, both frosted and clear. Some Bagley Carnival pattern items have the registration number molded into the glass (849118) and sometimes they have the wrong registration number.
My collection includes an interesting Carnival pattern fruit dish in clear glass, frosted on the outside, and with red polka dots on the inside. Sadly I don't have a frosted green vase. But keep looking - you'll find one.
This link will take you to a listing of Bagley glass on eBay - I hope it is helpfulhttp://www.glass-seek.com/newbagleyglasssearch.html
And if you use that link, a small commission goes towards supporting the Glass Message Board though me. So please give it a go.