How do you use CC and do a flashback, but just changing their hair and outfit? Mostly the hair.
@Apes has created a CC template for lipstick and hair only:
https://docs.google.com/document/d/1SaE4f4gI4YcRFc0JrMyuWwz-Q9nUQlYYSxcsJOeoF7U/mobilebasic
Bear in mind that if you already had a CC in the beginning of the story, having them change the CC for a flashback will complicate things.