I was wondering something, can you explain?

So whenever I see posts online it shows me a different version of the KitKat packaging when people mention it, which is mostly American people. Now I wonder why is the European KitKat packaging so different to the American one?

I mean the American looks like a dull red with white around the letters while the European one is a vibrant red with no white around the letters but it has a white oval on the logo with the letters on top