Those birds are OE based on Cream Legbars so they have the Blue Egg shell gene/mutation linked to the Single Comb gene, That means that when you cross your OE together it will be a toss up which of your F2s(the OE are F1s themselves) will lay Olive/green/Greenish colored eggs, you will not know until the hens start laying eggs.. I guess it will be fun times until the pullets start layingHere’s a pic of the rooster and another of one of the OE hens.