Pearl White Leghorns???

[Arve]

I got three "female", I hope, Pearl White Leghorns from a local farm. They said they came from Murrey McMurrey.
One look really "white", the two other ones are mainly white but has a slight tint on their necks and some around the rest of their bodies. Are they just dirty, or could they be some other breed?. I will try to post some pictures, but it might be to hard to tell.
Whats you thoughts on this???

Thanks