In one of my tanks I have 3 moors . One is a calico, one is a black moor and the other chocolate. All are eating and swimming fine and seem very healthy. He is my first chocolate and he is getting gray between his eyes. In case this is fungus, I have treated the whole tank with Pimafix. None of the others have this gray area. 1. Is chocolate a stable colour for a goldfish . Is he changing colours or perhaps I need to increase the time I have my lights on. I do not hope that he will turn gray overtime. He is a attractive colour now. 2. Is this more likely a fungus infection? Should he be in a GT tank or is he okay where he is. 3. If fungus do I treat the whole tank? / I assume so. 4. I am using PIMAFIX , is this the best treatment? thanks all. I eventually wish to breed some of my moors, and will start another thread about using different colours.