Which colours have you got? How long are your nails? If the colour change is a subtle one then sometimes you might not notice it and also if your nails are not long then you wont always get the colour difference. To test them have a glass of cold water and dip a finger in to see if it changes colour or alternatively have a glass of warm water.HandyAndy said:I have two polishes that are supposed to be mood changing except that they don't seem to work. I used top coat the first time I used it but didn't this second time and it has made no difference.