I get a few blue spotted eggs a week from my brahmas. Some have faint blue spots, hard to see. The egg I got this afternoon has darker blue spots all over it. They have layer feed and oyster shell available at all times. Their treats menu consist of whatever I have handy; usually bread, fresh corn, figs, and today they found some pecans in the yard that I had apparently run over with the car. They also free-range all day. The eggshells are very strong, hard to crack. I'm just wondering if the spots indicate a vitamin deficency or something?