Close to the end of the movie, where Wolverine is going away and Rogue is playing pool with the other school children, she stops playing and go to Wolverine. When the camera shows her first, she have got some of her hair caught in her mouth, but the very next time the camera shows her, her hair is very neat and tidy.
The reason her hair is white,Iforgetus, is because of the stress. Stress over time will turn hair white faster (that's why some old people have white hair and others have their natural color). Because of the immense stress on her when she powered the machine her hair started turning white.
Umm...maybe the hair fell down or something... I thought that was weird too!Why would they even keep the shot with a strand of hair across her mouth...
Fooseball is the soccer game with the little guys with rails going through their shoulders. You use the handles to pull the guys side to side and twist the handle to make them "kick". And yes, Rogue was playing fooseball, not pool.
Um.. for future reference watch the part when Rouge is in the thing on the Statue you can see it turn white. I think it is because of all the power Magneto transfered into her.
Most of these comments are about why she got her hair white. However, this slip-up is not about that. Besides, there is no explanation in the movie about her white hair because in the comics, she was born with it. The most obvious would be the electrons killing off the color making cells in her hair, as they did with magneto. (But they only did it to put the white in so she'd look roguish.)
Hair is made up of dead cells. That's why it doesnt hurt to get your hair cut. It is actually a common misconception that hair can naturally change colour. This is not so. Her hair could have changed to white due to the stress, but it would have happened over time, not in an instant. The smae mistake is often made by Stephen King in many of his books. See The Stand.