If I may remind you, Y/n and Yuuna have a special made uniform that changes when they go into another dorm. As soon as they out of the mirror that leads to the dorm, their uniforms changed back to the NRC uniform. Btw, the Amaryllis armband they have doesn't change, even when inside of Heartslabyul, Savanaclaw, Octavinelle, Scarabia, Pomefiore, Ignihyde, or Diasomnia