All my eggs where white to start with and then started to become abit cloudy brown but only two out of 6 are they deade ??? Angie k

No, its just that some ducks lay both brown and white eggs or blue and white, ect

I have a very un usual (incubator). My hen is broody so I brought some fertalised eggs that are ducks my friend did this with her duck eggs as well and it worked fine. So I was wondering why some of my white duck eggs are darker than Each other (they are all the same breed). Are they dead ???