I have 4 carpets. 2 irian jaya and 2 coastal. I cant say i have noticed that the coastals get an obvious blue or not, but both my irian jayas get extremely dark and their eyes get really blue.

its hard to say how many sheds they will go through and how much they will grow over a years time. There is many variables to that, one big one i think would be how soon you get the carpets on rats.