There are now a total of 10 fledgling zebra finches between the two pairs. Alex and Brix have three greys and two that are slightly more "silvery" colored than the others. I do not know if this is a true mutation or just a lighter grey color. Brad and Janet also have five, four grey pieds and one that is almost completely white with grey on its head and back. I did get some photos last night and will post them as soon as I can.