I recently moved a black ranchu from an outside pond to an inside tank. It is quickly loosing its black color and turning grey on the belly. No surprise, huh. On the one hand, I am curious about how it will turn out. One the other hand, I do not want to ruin a decent 16 cm oya. If I watch her turn color for a while inside, will the black return if I move her back outside?

Thanks,
-steve h