I was removing old batteries from a camera the other day. One of the batteries had leaked something very bright blue. I have seen batteries leak before and typically the colors look a bit like a corroded penny - pale green to white. This time it was a beautiful bright blue; what was it? I initially thought this could have been the metal making the connection was corroding as opposed to the color of the contents of the battery. However, I am not so sure about that.
Note: I believe they were double or triple A batteries and not LiION.