Color changing

[swill]

What are everyone's opinion on why Seahorses change color. I'm on my third pair of Reidi Seahorses which I believe are from a "Net Pen" (I wouldn't have bought them if I knew this but there is nothing I can do now I guess.)


...anyway, they were bright yellow in the fish store who told me they had had them for about 4 months. Within 3 weeks both have now turned black. Every set of Reidi I have ever bought have all turned black after weeks in my home. I have increased the size of my tank and am in the process of trying to lower the temp but I don 't think the temp is the issue as Im sure the fish store had them at around 78 degrees since they were in a tank that was connected to most all their saltwater tanks.

Why don't my seahorses stay the color they were in the fish store???