ceremonial / ceremonious
Of a rite versus full of ceremony in manner.
Ceremonial means of or used in a ceremony: ceremonial dress. Ceremonious means elaborately polite or full of form: a ceremonious bow. A sword can be ceremonial. A greeting is ceremonious.
Examples
Useceremonial robes
Usea ceremonious welcome
Avoidceremonious robes (If you mean the robes worn in the rite.)