When Voldemort kills Lily, she is wearing a sweater with high neck, long sleeves and it's red. When Snape comes in the room and sees Lily dead on the floor, she is wearing a blue blouse.
In the scene where Hagrid has dropped a "dead" Harry Potter, look quickly at George. He turns his head to the right and yells "Fred!" Fred has already been killed by Bellatrix Lestrange so it seems he may have forgotten this in a moment of grief.