When I started marking the eggs I just wanted to know how long they had been in the fridge. I considered whether to use a pencil or a marker. I thought about all the important things like: If I leave it in the fridge so I can find it will it still mark & If my kids get to it. Then I looked...
For the question about the food coloring. I remember as a kid coloring eggs that the egg also had a tint of the color the shell was done in. How ever I have no proof because I ate the evidence. I don't think you would call it science ether, I just called it dinner.