Oops, was just composing an answer to that point myself!
But IMO that doesnt make all brown glass EH.
Sorry, I missed this bit last night.
I don't think the 'likely Höglund' attributions given are solely because of the glass colour. It's a combination of disparate elements that on their own wouldn't necessarily point towards Höglund but that together may
do - including, yes, the colour, but also the gradiated effect, the strong naive form, the bubbles (along with the carbonised inclusions), the manner and quality of the finish, and the general similarity to documented Höglund designs (cylindrical mould-blown form with long hand-worked neck).