Deck, identical half red backs, half blue backs

[Philip N.(2)]

I found a deck that I must have put together a while ago, and now have no idea what the trick was that I was creating. The deck is made up of 26 red backed cards, 26 blue backed cards, identical set - so 26 random cards, and the same set of cards in the other back color. I can set them up so that the red backed set is in the exact same order as the blue backed set.
Any idea what this trick is that I was setting up?