Emmental cheese is naturally yellow? Cantal cheese is pretty yellow, but its also a bit dry. Orange is not natural, yellow can be. To get like an orange color, we can annatto seeds. I am no cheese maker so I can't talk too much about it, but my grandfather had a small farm, so I can only know what came from there.
Edit: That brie looks great! I like that the cheese hair is yellow. If it was the brie color, it would be too white and bright.