Has there been any living person throughout history born with eyes of different colors? I mean with a right eye of one color and a left eye of a different color than the right? Is that normal or abnormal?

Yes, there have been people like that. Even dogs!
I think its normal, since they are born with it. :)

Yes, it is perfectly normal. My friend has one super green and one super blue, and I know someone who has a bright green and a brown eye. :) It's perfectly normal and very cool.

(Picture from google images, just look up "two different colored eyes)

mine are somewhat different.