Very interesting. Yes, I think crabs and crays go that colour after 'cooking' with water or acids. But that one doesn't look very far down the stomach?
There have been reports of orange prawns/crustaceans in the Hauraki Gulf, which some people believe accounts for the success of orange lures down our way.
But at 20m is stuff really orange anyway?
I know the Atomic Sunrise has a very high UV content, so that might be one factor, along with the orange tint and the sparkle of the gold. JW rates that colour very highly for his charter work out of Sandspit.
Your observations that it's a stand out versus other colours on the day are fairly telling. The reason isn't clear, but none of us are fish! All that matters is you are nailing superb fish.