The egg yolk color is traditionally expressed in “Roche values” of 1 to 15.
The name “Roche” refers to the company Roche, which released the colour fan shown below a few years ago. Roche was acquired by DSM Nutrition Products GmbH a few years ago.
Our measurement devices work with a R-G-B-sensor which filtercurves work similiarly to the human eye (3-area method). We calculate the L*a*b data out of the red, green and blue ratio and determine the Roche-value with it. Our software saves the L*a*b ratio and the Roche-value.