You were a ghost. All ghosts except Napstablook were monochromatic colorblind however you had been born with the colorblindness and were used to it by the time you died. When you died you were cursed to be a ghost until you fell in love. Which was probably never going to happen. You had always been short and were still short even in death but everything is flipped upside down when a certain sans meets you.
4 parts