This is pink and black shirt worn in episode 1.04, a purple shirt worn in episode 2.03 and a scarf worn in episode 3.08. The pink one was described as being worn while Alison is impersonating Sarah. I think it's the shirt that Felix cuts in order to help Alison look more like Sarah. With that said, I did not see it later on, because she was wearing a jacket over her shirt.
