I only have a Kahl albino myself, they do tend to lose their red colors and lose definition and get more solid yellow as they get older, the sharp strain is supposed to keep their colors better with age, but I don't know if it's that much of a difference, I don't own any of those so I don't really know. Hypomelanistics/Salmons also tend to darken up with age, but I don't know if that would also be true of sunglows since they don't have any melanin with which to get darker.