In all respect, I tend to disagree regarding the block of gold for a jersey. It can work, especially if it's a darker shade (such as the mustard / oldish gold in my mockups), and on top of that, it'd be uniquely 'Pirates'. Giving them yellow instead, they join Parra, Brisbane, Gold Coast, and to a much lesser extent NQ, Melbourne, and Canberra using that colour.
The Dolphins could have gone the same shade of gold I'm proposing but the black in place of their white makes the big point of difference here. As it turns out, they've seemingly gone with a wishy-washy version of it, so it doesn't matter.
For my mockups, I'd have mostly black shorts for all three kits, so the gold jersey won't seem excessive. When the Broncos went with their mostly yellow away jerseys several years ago (the 'canary' jerseys), the only reason it wasn't a great look was because they also went with yellow shorts with it. That was too much yellow. Had they gone with their maroon shorts, it would have looked drastically better.