Top two peahens are the blackshoulder pattern. Their color is probably india blue.
Second picture. One the left is a hen that is in the India Blue color, pied pattern (IB Pied), middle is a peacock in BS pattern, IB color, so if from the hatchery as hens then they are all IB BS. Then the hen on the right is india blue in color, and barred wing/wild type pattern.
Ok, so why were they solid yellow at first. They didn't get any color until their feathers came in.The dark ones had some . The ones that were dark from the beginning only got darker when their feathers came in.