I think for OP any silver color is the same.
No, is not.
There are many silvers...Porsche silver.
As mentioned , for example, the GT silver came in 2005 when the Carrera GT was launched and it was exclusive for that model. No other Porsche model could have it, not even as PTS (Paint To Simple).
Years later, they introduced it in the line up. By 2010 if not mistaken. After being years a 4500$ option, in 2017 is a 850$ option on the 991.2 GT3.