Wow, three completely different bags!
I saw Stud P in person yesterday. That's a very small bag so be forewarned since your other two are larger. Also, in my opinion, the black didn't look as sharp in person as it does in that pic. The contrast between the black and gold doesn't stand out like I think it should. The studs are more muted in gold. Now the other combo does pop with the ecru and silver but I'm not crazy about the black and gold at all.
So between the other two, I like the pink. It's a stunning color and I like that bag more too. Love the yellow tassel on the borough though!