Not a dumb question at all.
There are only 2 "colors" of egg shells, White and Blue. The blue egg gene is dominant.
Brown eggs are a coating on the white shell, green or olive eggs are a coating on the blue shell.
That's very basic, of course there can be other factors...
So generally speaking when you cross a Blue egg laying roo on any hen, her genetics play in as well.
If she lays white, her daughters will lay blue.
If she lays tan/brown/chocolate, her daughters will lay green to olive.
ALl of this assume that your Ameraucana Roo is Homozygous for Blue...which he should be, but again in nature...things happen, lol!