This advice from the National Mass Violence Victimization Resource Center suggests what victims of a mass violence incident (MVI) should wear for a broadcast interview that focuses on their victimization.
The top priority is to wear clothing that is comfortable. If the outfit is new, it should be worn for a period before the interview to ensure it is comfortable for both sitting and standing. In addition to comfort, the outfit should not call attention to itself for viewers of the interview. If there is a t-shirt or sweatshirt designed to memorialize the MVI, it is appropriate to wear it. Some obvious suggestions are to wear neatly ironed clothes and shined shoes, and women should wear at least knee-length dresses and avoid low-cut blouses or dresses. Clothing and accessories that are inappropriate for television lighting and cameras are white or black clothing; fabrics that feature stripes, checks, or intricate designs; and any jewelry that dangles and makes noise with movement. Solid pastel shirts, blouses, and dresses usually are best for on-camera viewing.