As for the Magneton, the Shadowless vs unlimited indeed had some color differences, especially noticeable for the Holofoil cards.
And that first Japanese card is the same as the Derpy Pikachu & Meowth I have and have asked about before (without answer unfortunately):
@japanime, do you know where my Pikachu/Meowth with Onix at the back is from?
Greetz,
Quuador