Actually, the mutual "bannings" of eggs are a consequence of the different treatments and conditionings of egg production and hygiene requirements in the UK and in the USA. Washed and sprayed eggs need to be refrigerated.
http://www.businessinsider.com/should-you-refrigerate-eggs-2014-7?IR=T
As to the various colours of eggs, they depend on the chicken breeds or hybrids, and, to a lesser extent, on their food or, sometimes, on their living conditions, but there is no particular difference in edibility, nutrition and health values or taste - only the colours vary. The eggs of chickens roaming outside in natural pastures or gardens are, of course, healthier and taste better than those of "high performance" chickens confined to limited space and stress in factory farms.
http://www.hobbyfarms.com/7-chickens-to-raise-for-colorful-eggs-3/
https://www.mypetchicken.com/backyard-chickens/chicken-help/Is-there-any-nutritional-difference-between-H43.aspx