I was thinking it was a bit strange that all of the fish result in white fish fillets, even those like salmon, which are pink.
I wanted to suggest adding variety to the fillets- or maybe even add sashimi and other methods of cooking the fish.

I don't know if this is too much to ask, but I really think it'd add to the experience of fishing to capture a little bit more of the variety and realism.

This was done on purpose. It may change far in the future but at the moment there are no plans.