I bought a small red cap oranda goldfish about a year ago. She is in a well established 55 gallon tank with 3 other calico oranda goldfish. Lately, the red on her cap has faded and is almost completely gone and she is almost completely white all over. She gets plenty of tank light, still eats very well (is one of the largest goldfish in my tank) and acts normally so she's not sick. Her wen also has never grown at all. The three other calicos that I got around the same time, give or take a month or two, have had substantial body and wen growth in the last year. Her body has grown a lot but her wen is still flat. You have to look at her closely to even tell she is an oranda. Is there anything that I can do? Thanks in advance.