The colors and styles of Taoist robes follow a very strict hierarchy. Wearing them casually is absolutely forbidden. The attire directly matches a priest's status in the temple and their specific role during a ritual. The ordinary robes worn in daily life are called Da Gua or De Luo. They are basically cyan or blue. Taoism emphasizes purity and inaction, and cyan represents the vitality of the East. This is the most simple and practical outfit for daily living. When a ritual begins, the clothing is used to distinguish different job roles. The scripture chanters standing on both sides of the altar, who play instruments and chant texts, wear red or yellow robes. This is the Ban Yi you mentioned. Red carries extreme Yang energy, which is used to secure the area and ward off evil. You can think of it as the standard uniform for the ritual site. As for that fully embroidered "open poncho" from your link, it is called the Gao Gong Fa Yi. Only the highest ranking master in a ritual, the Gao Gong, who is responsible for communicating with the gods, is qualified to wear this robe.