How to measure egg boiling time?
Colour of the egg shell does not matter. Pigmentation is deposited, or not, depending on the breed of the bird.

There is in fact an astonishing amount of research devoted to egg cookery, as it is such an interesting topic. Whites coagulate at around 54C, yolks at about 62C. Which presents some interesting problems of course.

Here are some links that will be of interest. One is to a collection of links, often with further information in the comments.

http://www.metafilter.com/69134/Herv%C3%A9-This-the-man-who-unboiled-an-egg

http://blog.khymos.org/2009/04/09/towards-the-perfect-soft-boiled-egg/

http://openkitchenconcept.blogspot.com/2010/08/for-perfect-soft-boiled-egg.html

http://www.sciencebuddies.org/science-fair-projects/project_ideas/FoodSci_p046.shtml