Gail follows Dewey to actress Gail (Jennifer)'s house. They're outside. Gail is wearing a purple one piece dress, but for a brief moment after she comes out of Dewey's trailer, she's standing near the car wearing a purple top, but a cream skirt!! Look carefully...
OK, I agree with the first comment. I am watching Scream 3 right now so just for fun I thought I would come here and see if I could spot any of these slip-ups.... I couldn't find this one. Why? Because she is wearing the l. purple top and cream colored skirt the whole time. Not once is she seen with a light purple dress. (Well, yes, once.... that's at the end of the movie when Dewey asks Gale to marry him, but that dress is totally different...)