From red to white to orange to blue, fish flesh can land almost anywhere on the color spectrum.

What's behind this huge variation? A lot of things — from genetics to bile pigments. And parsing the rainbow can tell us something about where a fish came from, its swimming routine and what it ate.

Red yellowfin tuna: A classic of the sashimi counter, the yellowfin tuna is also the Michael Phelps of the fish world. And its athletic prowess has a lot to do with its ruby red flesh.

Sick Fish Suggest Lingering Impact of BP Spill

Apr 27, 2012

In November 2011, roughly a year and a half after the Deepwater Horizon disaster, commercial fisherman began catching red snapper with dark sores and lesions in the Gulf.

A group of LSU scientists studying the impact of the disaster is still finding large numbers of sick fish -- snapper in particular -- throughout the area of the oil spill.