For those that own or have seen them, how well do the older pastel and super pastel axanthics hold their color? Or the bumblebee axanthics?

It seems to me that the animals that are homozygous pastel tend to keep their silver coloring better and don't brown out versus those that have only one copy of the pastel gene ... The silver bullet versus super pewter, for example:

http://www.vpi.com/brag/super_pewter...compareson_pic