...the other day I cracked an egg in the pan and the whole thing was pink, with a larger red spot on the yolk. Grossed me out to see all that pink slime, so I scooped it all out of the pan...
I think I read here on BYC that someone fed their chickens leftover lobster shells and the next day all of the yolks were red and fishy smelling.
So the pinkish yolk could be that sort of thing, but is more likely diluted blood. I would have tossed it as well.