Why is my gineau pig's coat fading?

I got my gineau pig about 2 months ago and she's black, white and orange. Now, after these 2 months she has turned a very dingy looking black, and the orange is almost blonde now. I'm very concerned...is she sick?! She eats all of her food and I feed her romaine lettuce and carrots at times. She had one female baby gineau pig about 3 weeks ago, but she is acting normal and eating normal. Can someone help???????