Hi there
Hey, that's really neat! I like it!
I too have a Philodendron, it's never given me a completely white leaf, but has some interesting white patches.
I got it at a botanic garden sale. They said it was a cutting from an heirloom plant. I got one for myself and one for my friend. She keeps hers out in front of her home and someone who works at a local nursery stopped to ask her where on earth she got it, they'd never seen anything like it.