When Addy tries to leave for Chicago, every time she "warps" back to Red Lake Falls you can see in the far shot her hair is reddish-brown, not gray, indicating an error in the desaturation mapping until the scene shifts back to inside the car. You can also tell that it is not actually Lyndsy Fonseca driving as they let the car get a little too close before switching to the interior shot.
After Addy makes her wish the characters keep talking about "colour" but they live in a black and white world; how would they even know what "colour" is.