Fiorello’s is very good.
Talenti’s is not up to their usual standard, not much pistachio flavor.
I just tried the Leeuwen for the first time (bought at a sprouts in LA). They use Sicilian pistachios and the flavor is very intense and ‘nut-buttery’ for lack of a better word. It’s also a light brown color.
I found it almost too nutty and thought for a moment that a little artificial flavor might help balance it but if intense pistachio flavor is what your after it might be worth a shot.
My all-time favorite was made with a Pacojet from I think nothing but pistachios, water, sugar, and salt, so I definitely like intense flavor. One time I talked with an expert local gelato maker and he said he had to charge more for his pistachio because the Sicilian nut paste was so expensive.
https://tmagazine.blogs.nytimes.com/2010/10/08/we-made-it-ourselves-scream-sorbet/
Pistachio gelato in Italy is not green, also mostly tan.
Yes, green is unnecessary food coloring.