I'm having the same problem with my jewels.
They were in a tank with black sand and black rockwork for a long time, and their colors were excellent---flourescent pink with hints of purple and blue.
Now they are in a tank all to themselves, (they were with africans before!) but in a much smaller tank...it has lighter sand, and really crappy incandescent lighting. They look like crap.
I'm switching them back to something more similar to their old environment, ASAP...hopefully it will do the trick.
They were in a tank with black sand and black rockwork for a long time, and their colors were excellent---flourescent pink with hints of purple and blue.
Now they are in a tank all to themselves, (they were with africans before!) but in a much smaller tank...it has lighter sand, and really crappy incandescent lighting. They look like crap.
I'm switching them back to something more similar to their old environment, ASAP...hopefully it will do the trick.