credit card binding of isaac The Tarot Deck gold-credit-card - The Binding of

The ratio of border to center of the card can determine how high the card is graded

In fact, this effect extends to the entirety of Umbreon exs bodyUmbreon ex is outlined in gold

Each tin contains three Pokmon TCG: Pokmon GO booster packs and two sticker sheets for you to add a little Pokmon flair wherever you want

that is what I assumed as it's happened a number of times before (purple Gumdramon line is first to come to mind) but there are times where digimon seem to be in a color because of an overlooked attribute about them (all the black cards of vaccine Greymons or the purple cards of Garurumons) I think it was wise of them to not put all the leaders' draconic digimon in one color (red)