the question about the color changing is that it is a response to the fishes enviroment; visual, stress, emotional. The fish can change color in their pigments the same way humans become flush in the face.
my green severum and marbled goby will become darker when i walk up to the tank to feed them. It is a visual response to me. If another fish harasses it, it will change due to stress.
It is a simple answer to a complex response.
GL Keepers
lol....Its gone already... I have 5 notatus now.. traded with Rapps....my notatus for a few Notatus frys.. I have a few and Sencion has a few....when they pair up I'll sell the rest..