My RIR's lay daily and today when I went out to let them free-range neither would come out of the coop. They are both sitting in the nesting box area, one has a slightly pale comb and seems to be panting a little. They have plenty of water, food and shade (she is drinking but was not interested in the fruit I took out for a treat). When I retrieved their eggs one of the eggs was almost white in color. These birds always lay dark brown/chocolate colored eggs. What would cause an egg to change color? Any ideas??