First, if by Elephant Plant you mean the Taro or Elephant's Ear (Colocasia esculenta) then my best guess is too much sun. This is a tropical plant that likes filtered shade and warm weather. Another cause of foliage turning pale is frost or cold weather. Sometimes the oldest leaves will turn yellow or white before they fall off but this is a natural part of the plant foliage cycle. If you would like to send an image I can be more sure of my diagnosis and also confirm the identity of the plant.  The Elephant Ear  has huge leaves in a heart shape. If that sounds like your plant then direct sun on the leaves could be fading them to white. Keep growing, Marianne Binetti