The Memento Mori deck design was originally created by street magician and cardist Chris Ramsay for Murphy's Magic. Although this was a one-off deal, the deck proved to be so amazingly successful that Murphy's decided to follow it up with a blue version. Although Ramsay himself was not involved in the creation process (and has declined to endorse it), Murphy's Magic still proudly calls this deck by its given name.
What this ultimately means for you? More choice. The heavily detailed and carefully crafted design is still intact, but the blue colour scheme gives this deck a very different feel from the original.
The Memento Mori deck is also available in the original coloured version.