I have noticed that my Syno-Eup can change its general color dramatically depending on its background. Anyone else have fish that blend to their background? Also if you aren't happy with your fish's color, consider changing your substrate color. 
Its hard to tell but I have black rocks in my tank and I used a big 3 gallon black pot and a large white crock pot to show the fish color changes. When it's in the dark background, the fish is almost completely black. The longer is spends in a white background it will continue to get lighter. Picture in the skull is from when it was younger and when I first noticed this ability.
Youtube video below shows how dark the fish can be before lightening up..
http://youtu.be/PQgJqqS685E
Its hard to tell but I have black rocks in my tank and I used a big 3 gallon black pot and a large white crock pot to show the fish color changes. When it's in the dark background, the fish is almost completely black. The longer is spends in a white background it will continue to get lighter. Picture in the skull is from when it was younger and when I first noticed this ability. Youtube video below shows how dark the fish can be before lightening up..
http://youtu.be/PQgJqqS685E
