I didn't run on a tangent did I? I thought I was responding to some specific questions but if I did run on a tangent, I'm sorry. At any rate we did kinda hijack this thread but I don't think the op is too overly concerned (at least, I hope not ) as the initial question was answered.According to Rasputin, I was talking about C. margaritatus "bicolor" morph.
Since it's just a morphological as opposed to genetic difference, it's easier to just call is C. margaritatus. One of the things i ran into earlier last year was people actually calling the morph a C. bicolor and there was a bit of taxonomic debate over it. It got cleared up though as many of us noted the differences between C. bicolor and C. margaritatus "bicolor".