On the westerm side of the pond we call them tires 🙂
but then again we totally changed the spelling and pronunciation of Aluminum! (aluminium?)
I have an book with some old photos of the VW factory. Looking at the cars they appear to be model year 1957 having the oval window and low front fender mounted turn signals on the front. The photo shows a parking lot full of beetles, a mix of blackwall tires with chrome trim so I assume they are Deluxe versions and Wide white walls also on what appears to be a deluxe trim package. There are 100's of beetles in the picture and probably 40 % of the visible tires are wide whitewall tires.
My guess is, and it is only a guess for I cannot find any written reference to whitewalls being "official" or not, that Wide whitewalls were a factory option in 1957. I'd search out more old factory and dealer photos and see for yourself.
I've also read that many whitewalls were installed at local dealerships during this time period also.
All photos in my 58 owners manual are blackwall tires.
Some photos in my 52 -57 Bentley VW service manual show blackwall as well as very narrow (maybe 3/4 inch) whitewalls! No wide whitewalls seen.
I think it comes down to answering the question of what you like and go with it I am not sure there is a wrong answer here. I have noticed (and remember) that Narrow whitewalls seem to have became popular in the 1960's
Others may have documentation on this ?
"If you don't have the time to do it right the first time, when will you find the time to do it over again later?"