So are you saying that you can see the red border through the wrapper?
Well kinda...let me explain. All the card/sticker backs are white at the very edges except the foils, sketches and bonus cards. We can rule out bonus cards since they are in the celophane packs in the cereal boxes. Even the red puzzle pieces cards are white at the very edge. For the non-foil packs, in good sun light, I can tell whether the card edge is light or dark when looking in the white portion of the wrapper. Since all dark edge cards will be red edge cards, in a way you can tell they are red. I cannot do this accurately with the foil interior packs. The real trick is to move all the cards in the pack to either the top or bottom and to push the backmost card, only, to the other side to reveal the edge of the next to the bottom card. There is quite a bit of room in a sealed pack to move the cards up and down. But, as noted earlier, I don;t know how this rules out regular foil cards.
With that said, I did not open either a sketch or autograph card so ! don't know for sure if these show up as the next to the bottom card in the pack. Those of you who have found them, do you remember where the chase cards where in respect to the pack? I think I read Melty Way uncovered at least one in his efforts.