Hello! I will be assisting you today. This color change would indicate that the area is healing. As you have found out this method is not only dangerous but not very effective. The are should continue to heal with the hydrocortizone application. To treat the warts it is best to go to the walk in clinic or your regular doctor. There are a few different method s to remove them without the high risk of injury. I have met people that used this method and have become permanently scarred.