Sevillian- I know *exactly* what you mean about the P21s vs. Souveran! I tried the former on my Jag (ss metallic gray, not quite silver..) and it was so awful that I stripped it off and redid it with Souveran.
ALTHOUGH... the FK1000P I like so much has that "synthetic"/bright look Funny, it gets *infinitely* more compliments than any other LSP I`ve ever used (pre-Pandemic strangers would come up to comment *all the time*, actually got to be a nuisance), but I dunno if I could stand it on the Jag. Eh, that`s a weird paint (that Jag quit using over all the issues with it) anyhow...definitely "not silver" despite being *almost*. I mean..I`m splitting hairs here: light gray metallic is awfully close to silver no matter what I say.