I know all my family up to my grandparents, with the exception of the grandfather on my mother's side. At the time my mother was conceived, my grandmother was having an affair so no one in my family knows for sure who the grandfather was.
In high school we learnt that blue eyes are a recessive trait and brown eyes are a dominant trait, as such I should be able to figure out who my grandfather is, but I only studied up to that level and I want to check with someone more knowledgeable than myself if it is correct.
So here's my reasoning: I have blue eyes, meaning I have two blue eyed genes and got one from my father and one from my mother. My mother has brown eyes, meaning that she has one brown eyed gene and one blue eyed gene to pass it on to me. My grandmother has blue eyes, so she passed one on to my mother. One of my potential grandfathers had blue eyes, so if it had been him my mother would have received two blue eyes genes and have blue eyes. But she has brown eyes so it must be the other potential grandfather (who's eyes I don't know the colour of). Can someone tell me if this is correct, and if not, why not?