My eyes do the same thing, primarily blue, but change to green. I always thought it was reflected light or something that did it. I think it's kinda cool, though.

I would think the disappearing conversation would mean blocked, too, BUT I will note that when my crazy step mother was blocking me on FB, our old conversation was still available for viewing in the inbox, it just said, "You are unable to respond to this conversation". So, I dunno.