what I have seen in the years I have bred is eggs getting creamy brown but I have come to conclude that it depends on what kind of medium the eggs are in. My eggs on moss pick up the color from the moss for sure. The ones on vermiculite will also pick up kind os a metalic sheen from the vermiculite. I have had eggs on hatchrite and noticed minimal color changes except on the very ends of the eggs. HOw far along are your eggs at this point?