"Click" it to enlarge it. It's rare for a photo to capture the true blue of a red's tail. I almost never get it, but I got it above. Answer: Chromatophores, specialized cells actually generate the color.
And, here's Archosargus probatocephalus, my nemesis for a number of years, locally. I called them "The Poor Man's Permit" in a story I wrote for Fly Fishing in Saltwaters back in 1997. Now I catch them with flies all the time. Watch out for their human-like teeth--CHOMP!! Double "click" this photo, and you can see that it's hard to tell this fish's smile from Jimmy Carter's toothy rictus. Thank God, this fish didn't lecture me.
And for Heaven's sake, look out for her dorsal spines! No venom here, but they're sharp!:
They sure are drama queens! I hope they don't mind my mocking their behavior. But they DO make a big show of it, really. I've got a few photos of the aftermath--foaming water at a distance, mostly. Some damned close and really out of focus, too. I hope you understand. I'll spare you the drama.