Sue Oujo no Koshire - Sono Kage de Hamerare, Tsukai Suterareta Oujo no Kagemusha no Shoujo ga Jibun no Shiawase wo Tsukamu made

Mary is an orphan who was given the special ability to copy other people's hair color. As a shadow of Leonora, the youngest princess of the Granberg Kingdom, she is given a strict education as a lady's maid, and finds herself forced to do almost all of Leonora's work. One day, Alberto, the heir apparent of the frontier count, is chosen as Leonora's prospective fiancée. However, Leonora is unhappy about the engagement and orders Mary to find his faults in order to break the engagement...?