I have always fed my chickens grower food with oyster shell calcium to supplement. That has not changed, but our BR and EE/american game, who previously laid tan/blush eggs, are now laying very, very pale pink to nearly white eggs. Like others have said, there has been no change in the eggs' taste or the hens' ability to lay, just the outside color.
Of note, we did move a week ago, and I have attributed the alteration in color to the move. I was under the impression that moving stresses hens and decreases their ability to lay, so we did not sell any eggs the last week or two before the move so we would have plenty for ourselves. DUMB move. LOL. This move not only didn't decrease their laying ability, but one of them who had been broody (raised her chicks already) resumed laying as soon as we moved. It's gotta be all the fresh, green grass and the mountain air. We are getting 5-6 eggs a day with no break in laying, not even on moving day (one of them even laid an egg in the box during transport).
Since they didn't decrease their laying #'s, I was attributing the lighter eggs to the move, but not EVERYBODY's eggs are lighter, only the barred rock, the EE/game cross, and the light brahma's eggs are not as smooth/sheeny as they were. Oh, and one of my EEs eggs are bigger than they've ever been. Gotta be the mountain air.