These colors are real- if you were to swim up to this tube anemone today with your mask and snorkel, this is what you'd see.  No flash, no Photoshop.  

The tube anemone comes out of the sand, its tentacles bend with the surge, and somehow it catches and eats enough plankton to keep up with this rigorous schedule, grow, and mate.  If you disturb it, faster than you can blink it withdraws into its sand-colored tube.  The only way to see it is to move slowly and be patient.