That's very disappointing, I would demand a refund. Dark egg laying breeds have the genetic potential to lay dark eggs but it doesn't necessarily mean they will lay dark eggs. With any dark laying breed you usually get a light egg here and there, but a whole dozen is a bit ridiculous, especially early in the season when eggs should be their darkest. The problem with hatchery birds is that they are bred for quantity not quality, so all eggs are place in the incubator rather than just the darkest. Without selection for dark eggs the strain soon becomes a flock of regular layers. There is a yahoo group for dark layers, you can find some good breeders there. Good luck!