Is Daphne changing color?

[Lori, Daphne, Lucy & Pippa]

Daphne is now 16 months old and I had assumed that her coat is the one she will have always. As a baby she was creamy colored. As she grew and her coat changed, she is now mostly white with just a hint of creaminess on her ears and tail. She had her last grooming on June 7 and everything was normal. Three weeks later, we were visiting my parents when my Dad pointed out what I thought looked like a dirty spot on her back. Since then, the spot appears to be getting a little larger. The fur there is a dark cream and seems to be coarser than the rest of her. Everyone always says she feels like a cotton ball. The larger part of the spot is closest to her tail and seems to be inching slowly up her spine.

I don't know if this is anything to be concerned about or just a normal occurrence.  A CGC trainer suggested to me that she may be becoming parti colored. Thats kind of funny since Lucy (her Mama) is not a parti and neither are her parents. Her father is an ice white mini poodle. Others have said it looks like what happens when dogs chew on certain spots. I have never seen her chewing on her back.

Any thoughts?

[Lori, Daphne, Lucy & Pippa]

Thanks Donna, you are always so sweet! I really appreciate the discussion links! Very interesting reading. And it all definitely makes me feel better.
Loved your interview by the way!