A long time ago hens did not lay white or brown eggs but eggs in primary colours: red, yellow and blue. Since, depending on the colour of the eggs, their taste and quality varied, the farming industry split into red, yellow and blue industries catering for different markets. Those industries that dealt with the respective eggs became over the years highly competitive. And what was initially no more than a common understanding, namely, that hens laying red eggs belonged to the red industry, while hens laying blue and yellow eggs belonged to the blue and yellow industries, turned over the years into customary egg law, with each industry having its clearly demarcated area of competence. As it happened, due to interbreeding, some hens normally laying, for example, red eggs would very occasionally lay purple eggs or orange eggs. Also on occasion, some hens would stop altogether from laying eggs of a primary colour, but would lay orange, purple, brown or green eggs. These eggs and hens presented a problem, albeit not a severe one, as they remained very much the exception. Hens laying blue eggs were kept apart from hens laying red eggs and from those laying yellow eggs. Nevertheless, solutions to these problematic eggs and hens had to be found.