Scoly long term colors

I remember from Bio that the algae on a coral determines it's color. Without any algae, the coral would just be white. So maybe the algae has diversified or changed over the span of life in your tank?

 

Yes, 50g Rubbermaid stock tank... And the commute may only be 2 minutes, but the afternoon nap made it longer! That and the fact that I forgot to seal my camera when I started taking underwater pics so I hope my camera isn't fried now

The large chalice is Miami hurricane. It's a bad picture of it. I swear the frag is Miami hurricane also but my friend thinks its different because it is really turquoise and the eyes are pink instead of orange? I think it's just because it is more light up higher though...

Yes, thank you. I believe the algae is called zooxanthellae. Corals can also create their own colors as a "sunscreen" with amino acids, chromoproteins and carrotenoid proteins.

In tanks the algae that host a coral changes a lot... Real mature tanks will have extremely diverse populations and this usually leads to gorgeous colors. Even I have had corals change colors between tanks. But this gets into a few other factors also then.