Heritage chickens lay eggs in an assortment of different colours depending on their breed. All eggshells are actually white and then pigment is added to the shell just prior to laying. There is no difference in either the taste or nutritional content of the egg but the colours are fun and add interest to your egg basket. Commercial eggs in North America are generally white and in Europe they are commonly brown to meet consumer preference. Raising heritage chickens allows you to fill your egg basket from an array of colours and shades. Not only is this attractive for your own table but if you sell your surplus eggs then you will have a competitive advantage at the farmer’s market.
For a sustainable flock you should settle on a single breed of chicken and raise them exclusively, unless you have the space and structure to keep the breeds completely separate from each other to avoid crossing (See Easter Egger/Olive Egger for more on crossing chickens for coloured eggs.). If your city regulations prohibit roosters than your flock wont be sustainable anyway and that’s the perfect excuse to try an assortment of pretty birds and eggs. Below is a short example of breeds by egg colour.
White Egg Layers: Ancona, Dorking, Leghorn
Pale Brown/Beige Egg Layers: Orpington, Plymouth Rock, Wyodette
Brown Egg Layers: Rhode Island Red, Australorp, Barnevelder
Dark Brown Egg Layers: Marans, Welsummer, Dark Brahma
Pink/Plum Egg Layers: Croad Langshan
Blue & Blue/Green Egg Layers: Arcana, Ameraucana, Cream Legbar.