I can't speak for other breeds but the earliest texts I can find referencing Langshans (and therefore what eventually became the Croad Langshans when they bred the three "styles" {Modern, Croad and German}) doesn't mention purplish eggs, so I'm assuming it was just something that was selected for at some point. Which for that breed at least means I don't consider egg color that important anymore than brown. Over the years I had some that laid a purplish tint, and had some that laid very dark brown (guess that makes some sense due to the Langshan being used to create the Maran) and quite a few that laid brown with darker brown specks. In general I think that people get way too obsessive about egg color and it lends itself to just another "fad".
For what it's worth the APA standard still says blue eggs only on Ameracaunas. Again though I think confirmation and productive capabilities are far more important than egg tint. (Color is important but shade of that color is not in my mind, but that's just a personal preference)
check in my gallery he's the little white stag
