"Lord Of The Rings" has already appeared in our list once, and this is an error that covers not only all three of films in that movie series, but all three in companion trilogy "The Hobbit", too. It's all to do with Orlando Bloom in the role of Legolas.
In the "Lord of the Rings" films, Legolas has piercing blue eyes. You can't help but notice them, they're one of the character's signature traits. In "The Hobbit", he's playing the same role, but his eyes are brown. The same director, Peter Jackson, made both films, so this is the sort of thing he should have realized. Maybe, at some point between the two sets of stories, Legolas had some kind of accident that permanently changed his eye color. Or maybe Bloom just really hated the contact lenses.