Blue and Green Eggs

A relaxing weekend. HL and I spent yesterday at Congham Hall - a birthday treat. We had a really nice and pretty healthy lunch in their restaurant followed by four hours in the health spa. The best bit was a hot jacuzzi in the open air - and a massage. 
Today we went over to Walcott to look at an award winning house with an interesting garden room extension. It is food for thought as we are planning to do something similar but on a smaller scale, if we can afford it...
On the way home, HL was just talking about needing some eggs when we came around the corner and I noticed a roadside stall saying "Eggs!"
On taking a closer look, the eggs mostly turned out to be beautiful shades of blue and green. I have never kept hens and don't often come across these unusual coloured ones so I read up on it and found out as follows:

Some birds from South America, such as the Araucana, carry a dominant gene for blue egg shells.   In addition to calcium carbonate and the other typical minerals, blue egg shells contain oocyanin (thus the genetic symbol O; note the root “cyan”) which is a byproduct from the body’s production of bile.  This blue pigment is not a coating like brown but is throughout the egg’s shell.  Thus, the blue egg is also blue inside (before the inner membranes dry to a papery white) and is more difficult to see into when candling.  However, like brown pigment, the amount of oocyanin will also lessen throughout a hen’s laying cycle, and she will lay progressively lighter blue eggs. 
Interestingly, the gene for blue egg shells is closely related to the gene for a pea comb.  A pea comb is a good predictor of the presence of the blue egg shell gene, but a chicken can have a pea comb and have white-shelled eggs.  There is now a theory that blue-green pigments in egg shells help to protect the growing embryo from solar radiation.  This may be why these pigments are often found in more breeds and species from tropical regions.