I put a small black 'X' on the fake brown eggs with permanent marker. They don't care, and then I don't try to eat the fake ones, lolI'm trying to convince them that they don't all have to use the same two nest boxes. They tossed out the golf balls I tried. The brown ceramic eggs work really well with them. Unfortunately I can't tell them apart from the brown eggs without candling.
I think they will toss the white ones out of the nests. I've never had any white layers. Had an EE that actually laid an egg this color of green though.